The following is an example of Geoza Mana use (Mysticism / Witchcraft, etc.) in action.  The game mechanics will be interspersed with a narrative account of the events.  This example uses the same situation as the example of Sorcery, to illustrate how different Origins would approach the same effects.  Note that specific spell examples may refer to spells that have been optimized (either fully or partially) using rules for magical research in Geoza.
Jarrett noticed the afternoon sun dropping below the horizen as he rested on the southern slope of an unnamed hill in northern Pelos.  He'd been climbing up and down these hills all day, and still hadn't found the landmark he was searching for.  He sighed heavily, and started to move up-slope again, when movement to his left caught his eye.
He looked west, into the afternoon sun, and saw again what had caught his eye:  goblins, moving his way.   There were only three of them, and they were still a ways down-slope of him, but they could probably move faster over this hilly terrain than he could.  This was a definite problem.  No use trying to avoid them, or running away.  He'd have to try to take them out before they reached him.  He had his walking staff and a good dirk at his belt, but those goblins would swarm over him in an instant if they could close with him.
Situation Jarrett, a Mystic, is a little lost in the foothills of the Skyreach Mountains in Pelos.  He spots the 3 goblins headed his way at a distance of about 80 paces west and down-slope, and decides to stand and fight.  Jarrett's relevant characteristics are as follows:
Aura 8 Mana Lore 8
Willpower 7 Mana Capacity 80
Endurance 6 Stored Mana: 12 Water
Hardiness 6 18 Fire
Perception 7 22 Earth
Quickness 6 10 Air
Jarrett's Omnessence Expertises:
Conjuration 4 Energy 8
Creation 8 Organic 8
Destruction 7 Physical 8
Divination 8 Reality 4
Manipulation 8 Spirit 6
Transformation 7 Will 6
As can be seen from his ability levels, Jarrett is an experienced Mystic, with a variety of options as to the kinds of effects he can Shape.  Jarrett's Option Point total for each Action Interval will be 8.
The Mythguide determines the local availability of Mana in this area.  He is using the optional rules on Mana Aspects, so he gives Jarrett's player the following Availability information:
Local Manifestation: Shallows Average Availability level:  5
Earth 9 Air 6
Water 2 Fire 6
Jarrett leaned against his staff and opened his senses further, taking in the Mana flowing around him.  He could sense the solidity of earth very strongly here - not unexpected in the mountainous foothills.  He could also sense the faint dark fluid feeling that told him there was water at a distance - a mountain stream, perhaps, or an underground source, but not strong, here.  Somewhat surprisingly, Fire was also present here.  Perhaps it was a reflection of the burning afternoon sun, or maybe an extension of something hidden deep underground, as fire often was.  Air, of course, was present as well, not as strongly as the Earth, but he could feel its movement not just in the wind on his face, but also deep inside in that part of him that could sense the Mana.
Jarrett reached out with that additional mystic sense and began to draw in the Air Mana toward him, feeling it coil in tendrils of wispy essence in his aura.  All living beings had an Aura, and sometimes you could sense something extra held there.  Usually, that meant a mystic, one who could feel the Mana, and use it.  He drew in a deep breath and refocused his attention on the approaching goblins.
Jarrett spends one Action Interval (the Access Interval for Mana) gathering Air aspected Mana.  Jarrett's player selected Air aspected Mana for two reasons:  one, Jarrett doesn't have much stored at the moment, and two, he's planning on using a Manipulate Physical effect - which Air Mana is appropriate for.  Jarrett hasn't stored much because Air aspected Mana is usually available at a decent level, wherever he goes.  It may drop in level of availability sometimes, but not drastically, and not for long periods of time.  Jarrett's player wants to use it for the effect he's planning, so he gathers it now, since he has some time.
In the Access Interval he just spent gathering Mana, Jarrett can gather 24 points of Mana.  His Aura is 8, the Availability Level of Air aspected Mana is 6, and Mana has an Access Facility of 10.   Adding those ratings together (8+6+10) yields 24 points of Mana in one Access Interval.
Jarrett doesn't have to store Mana that he's just gathered if he's going to use it immediately, but he has the excess Capacity in his Aura right now, so Jarrett's player decides to store it anyway - you never know, he might change his mind about what he wants to do, and if he didn't use the Mana as soon as he finished gathering enough, he'd lose it all and have to start over again anyway.
Jarrett then makes a Fatigue Trial at Difficulty 4 (10 - Availability Level of 6 for the Air aspected Mana he just gathered).  Jarrett has an Endurance of 6, so his Fatigue Trial Asset is 9 (base 3 for an attribute trial, plus his Endurance Rank of 6).  Subtracting the difficulty of 4, his Adjusted Trial Chance is 5 - not bad, but not good.  Additionally, Jarrett has to modify the difficulty up one more point because he already accumulated a level of Fatigue from climbing over the hills that afternoon.  So his final ATC is 4.   Jarrett's player will have to roll well not to get another level of Fatigue from gathering that Mana - the player rolls, and gets a 3.  Whew!  Just under the number he needed.  Jarrett evades Fatigue for now.  Jarrett has 1 OP left this Action Interval to do something, so he decides to gather some more Air Mana.  He's just added 18 Air Mana to his Aura, and has another 6 points gathered for an effect, but he'd like more going into a fight.  He spends another Action Interval gathering Air Mana, with similar results.
Jarrett scanned quickly, tracking the goblins, and then delved into his mystic senses again, drawing more of the Air Mana into his Aura.  He gathered as much as he could into his Aura, and then, when he couldn't draw in any more, he began building up what he thought of as a "working pile" of Mana to Shape an effect with.  He focused his attention on a nearby rock a little larger than his head.  Sweat breaking on his brow and running down his back, he began Shaping the Mana around the rock, adding more from his recently stored supply as he built up the effect he wanted.
Jarrett's player rolls another Fatigue Trial for Jarrett, but rolls a 5 this time - not good enough.   Jarrett's Fatigue Level is now Tired, a Hindrance (+2 to difficulty).  Jarrett is now finished gathering another 24 points of Air Mana.  He doesn't have any capacity left in his Aura, but can add these 24 points of Mana to the 6 extra he gathered last interval, and use them for an effect.  Note: he could continue to gather Mana and not store it, as long as the first thing he did after he was finished gathering the Mana was to Shape an effect with it. 
The effect Jarrett's player has in mind, however, won't require that much Mana - at least, he hopes it won't.   Jarrett's player tells the Mythguide that what he wants to do is hurl that rock at the nearest goblin.  Jarrett uses the following Manipulation/ Physical Mana Paradigm: Hurl Rock (an effect Jarrett has used before, and has fully optimized):
Scope Basic Scope (2 points)
Scope is affecting a State (1 point).
Jarrett will have to expand the basic range to Sight, which is an Impressive level of Scope (Jarrett has optimized the cost for this component down to 10 points of Mana, the minimum for an Impressive effect level).
Potency Just moving the rock is a minor alteration to the rock's physical state (currently at rest), which is a Moderate Effect (9 points - Jarrett hasn't optimized this because he wants to be able to alter the potency of this spell if he has to).  The base Conflict value for this spell is12 points, which will give the hurled rock an attack value of 4 - about the same as an average longbow arrow.  Total of 21 points for Potency.
Intricacy Intricacy for this paradigm is Slight (optimized to 1 point).
Temper Aspects Jarrett will need to Target the hurled rock, but that doesn't cost any Mana, just a Targeting Trial.   Jarrett's player doesn't see a need for any other Temper Aspect. He could have picked Removed, if he had wanted to hurl a rock which was some distance away from both him and the goblin, but because this rock is lying basically at Jarrett's feet, the player doesn't think its necessary.
The Mythguide is familiar with this paradigm - Jarrett's player has been using this spell for a little while.  The total cost for this paradigm will be 35 Omnessence.  A fairly easy effect, well under the limits of the Mystic Jarrett's abilities - Jarrett has ratings of Manipulation 8 and Physical 8 (and his Mana Lore rank is 8), so Jarrett has an effective Omnessence limit of 64 points of Mana.  The Configuration Might of Mana in Manipulation / Physical is 72, which means he can create an effect of up to 64 Mana  - quite a bit more than this little spell requires.  Jarrett pays the cost of this paradigm with the 30 extra Mana he just gathered but couldn't store, and adds 5 Mana from his stored Air aspected Mana, for a total of 35 points.
Jarrett concentrates as he finishes Shaping the effect he wants, adding in some of the Mana he just stored to give this rock some Oomph!.  The rock lifts from the ground and hurtles toward the nearest goblin, about 50 paces away.  Jarrett guides the path of the rock in the final moments of his Shaping, and watches it strike the goblin on the left leg, just above the knee.  The goblin yells in pain and glares up at Jarrett.  Uh-oh, Jarrett thinks, I've just made him mad!  But the goblin is hobbling as he climbs toward Jarrett, so it did slow him down some.  Hmmm, Jarrett thinks, I need to put a little more pep into the next rock...
Jarrett finishes Shaping the effect, and makes an Effect Trial to determine if the effect works.  His base for an Effects Trial is 4, half of his Aura.  His rank for the Trial will be his average effective Configuration Expertise, which is 8 for Manipulation/Physical.   That gives him an Effect Trial asset of 12 for this paradigm.  His difficulty is the Affinity of the rock - nothing out of the ordinary, its affinity is 3.  Plus, he's got two levels of Fatigue (+2 to difficulty), so his final Adjusted Trial Chance is only 7 (12-3-2=7).  Jarrett's player rolls another 5 - good enough for a Complete Success.  The effect will work.
Jarrett now has to make one more roll - the Targeting Trial to see if he can actually hit the goblin that this rock is now whizzing towards.  His base for this trial is equal to his Aura, 8.   His rank for this trial is his Perception rank, 7, which gives him a Targeting Trial Asset of 15.  Not bad.  But added to that is the Attack Value of 5 for the paradigm, for a total of 20.  Difficulty starts at 2 for a Targeting Trial, but again, Jarrett is Tired, and that can affect his accuracy, so difficulty jumps to 4.   The Mythguide assesses the situation, and says that is moving at a fast walk, which will add another +1 to the difficulty.  Since the goblin probably isn't expecting a rock to come flying at him at the moment, the Mythguide decides the goblin won't be dodging anything, but the goblin's tough hide will add another 2 to the difficulty.   So the final ATC for this trial is 13 - an almost certain success.  The player rolls a 9, which is a Complete Success.  The rock hits!
The Mythguide rolls at the same time, because he wants to figure out how the Erratic Nature of Mana is going to affect this paradigm.  He rolls 2d5, gets a 7, and subtracts that result from the average Availability level of Mana.  He uses the average availability, rather than one of the Aspect ratings, because he's not concerned about just Air Mana, but about how Mana in general is behaving in this location at the moment.  Subtracting 7 from 5, he gets -2, possibly a drop in the potency of this effect.  But since Jarrett is using an appropriate aspect of Mana for the effect, the Mythguide decides to ignore the drop in potency and let the effect happen as planned.  He rolls a quick die for hit location, and announces that the rock struck the goblin in the left leg, just above the knee, causing a Wound to that leg and making the goblin cry out in pain.
Jarrett draws upon the Mana he's stored in his Aura, and begins Shaping a greater effect.  He's going to hurl the next rock so fast and so hard it'll knock that ugly little goblin off the side of this hill!  Jarrett Shapes the next effect as he tracks the goblin's progress up the side of the hill.  As it draws closer, he sends another rock, slightly smaller, hurtling at the wounded goblin with incredible speed, smashing into the goblin's chest, caving in his lungs, and sending him rolling end-over-end down the side of the hill.   One down, two to go, Jarrett thinks.
This effect is basically the same as the last one, with a massive increase in Potency.  Jarrett's player decides to allocate 33 Mana to Conflict, for an Attack Value of 11.  This rock is going to smash that goblin flat!  The total cost for this paradigm will be 57 Mana (13 for Scope, 42 for Potency, 1 for Intricacy, and 1 for the Alter Potency Temper Aspect).  Jarrett doesn't bother gathering any, but allocates all of his remaining Air Mana (23), and all of his stored Water Mana (12) and Earth Mana (22) to finish it off.
The Mythguide notes that although Jarrett used other aspects of Mana, the vast majority of the Mana he used was Air or Earth Mana, both of which are appropriate to hurling a rock with great force.   He judges that no alteration to Potency is necessary, because Jarrett is using appropriate Mana Aspects.
Note: Jarrett can alter the potency of this optimized spell because he hasn't optimized any of the Potency components.
Jarrett rolls his Effect Trial again, and succeeds, then rolls for Targeting.  This time, the Mythguide says, the goblin will attempt to dodge.  Jarrett's player points out that this attack is stronger than the last one, and the goblin is wounded and slower.  The Mythguide agrees, but says the goblin still gets a chance to dodge, since this rock won't be a total surprise.  The Mythguide rolls for the goblin, and announces that the goblin managed to achieve a Marginal Success on his dodge, despite the slope and his wound.  Jarrett's player grins and rolls his Targeting Trial, which has an ATC of 19.   He rolls a 4, which is a Mythic Success!  Even taking away one degree of success for the goblin's dodge still leaves Jarrett with an Extraordinary Success.   The Mythguide announces that the rock smashed into the goblin's chest and inflicted a Mortal Injury to the goblin.
Jarrett glanced over at the other two goblins, who had climbed up-slope and were now approaching very quickly across the hillside.  Have to take out both of them with my next Shaping, he thought.   Another rock won't do it.  Jarrett reached out one more time to the Mana, this time feeling for the ethereal heat that indicated Fire Mana.  He drew it to him, feeling the sensation of mystical heat as it filled his Aura.
Jarrett spends an Access Interval gathering Mana again - Fire aspected Mana, this time.  He's planning on creating a fireball big enough to catch both goblins in it as they charge him, so he wants more Fire aspected Mana to create it - he's going to be cutting it close as he Shapes it, and doesn't want any surprises from unpredictable Potency.  Jarrett's player rolls a Fatigue Trial, and gets a 2 - he avoids more Fatigue, and has stored 24 more points of Fire aspected Mana to work with now.  That brings his total amount of stored Mana to 42 - all Fire aspected Mana.  He'll need even more for what he's planning, because he hasn't practiced this effect enough to optimize the cost yet.  Jarrett spends another Access Interval gathering another 24 Fire Mana, bringing his total to 66 points of Mana.
The effect Jarrett's player has in mind will be a Creation/Energy Mana Paradigm:  Fireball.  He's done this before, and has partially optimized this effect:
Scope Basic Scope (2 points)
Scope is affecting a Form (3 points).
Jarrett will have to expand the basic range to Sight, which is an Impressive level of Scope (10 points).
Additionally, this will be an Area effect, so that's another Slight Scope increase (1 point), and gives him a basic radius of effect of 2 paces.  Total cost for Scope is 16 points.
Potency Jarrett needs a powerful effect for this one, he won't have time to try again.  The player allocates 21 points of Mana to Potency, which will yield an Attack Value of 7.
Intricacy Intricacy for this paradigm is a little higher.  First, Jarrett is creating the fire, which is a Slight effect (3 points).  Jarrett also needs the fire to have elemental effects (i.e. it will be fire, not just have the appearance of fire), which is a Moderate effect (9 points).
Temper Aspects Jarrett will need to Target the fireball, but that doesn't cost any Mana, just a Targeting Trial.   Also, he puts 1 point into the Widen Temper Aspect, which increases the radius of effect for this Shaping to 6 paces in radius (Variation Facility for Mana Widen Aspect is 2 - for each point of Mana allocated to Widen, the area is increased by 2 times the base increment.  The base is 2 paces, so each point adds 4 paces.  2 + 4  = 6 paces total radius).  Jarrett doesn't need to use the Alter Potency / Intricacy Temper Aspect, because he hasn't optimized either of those components.  Only Scope has been optimized so far.
Total Mana cost for this Shaping is 50 points of Mana.  That's just under the limit for a Creation / Energy effect.  His expertises in Creation (8) and Energy (8) enable him to spend up to 64 points of Mana, but the Configuration Might of Mana in Creation / Energy is only 54, which limits Jarrett to spending 54 points of Mana on this effect.
Jarrett spends the next Action Interval Shaping his fireball effect.  He uses most of his stored Fire aspected Mana (50 points) to fulfill the required cost for this Shaping.   As he finishes Shaping the effect, Jarrett's player rolls the Effect Trial.   Base = 4, Rank = 8 (average of Creation / Energy, limited by Mana Lore).   Unlike the Hurl Rock paradigm, where the direct magical effect was targeting the rock to be thrown, in this paradigm the two goblins are the direct targets of the magical fire.  So the difficulty for this Shaping will be the higher Affinity of the two goblins.  The Mythguide rules that they are average, and thus the Affinity will be 3 (each goblin has an Aura of 5, based on their average Empathy ratings of 5.  Mana Affinity for living creatures is 5 - (Aura / 2), or in this case, 5 - (5/2).  Five divided by two is two (round down in this case).  5 -2 = 3, which is the goblins' Mana Affinity.  Pretty average - just like the rock.  Of course, that base Difficulty is increased by Jarrett's two levels of Fatigue (+2), so final Difficulty for this Effect Trial is 5.  4 + 8 - 5 = 7.  Jarrett's Adjusted Trial Chance is 7.  The player rolls a 4, which results in a Complete Success for this Shaping.
In this case, the Mythguide points out, the goblins will get a Passive Resistance Trial to resist the effects of the fireball.  Their base is their Mana Affinity (3), and their rank is their Willpower attribute (the Mythguide again rules that they are average in this regard, and gives them a 5).  The difficulty for passive resistance to a Mana effect is the Effect Might of the Shaping.  The total of potency and intricacy is 33 points, which from the Effect Might Chart on page 141 in the ARIA Reality chapter, gives an Effect Might of 4.  3 + 5 - 4 = 4.  The goblins must roll 4 or less to have an resistance to this effect.  The Mythguide rolls a die for each goblin, and rolls a 4 and a 7.  One goblin fails to resist, while the other barely manages a Marginal Success on resistance.   He'll be a little less affected than the one that failed.  The Mythguide also considers the Erratic nature of Mana, but decides since this Shaping used Fire aspected Mana, no Potency variation will apply, and so doesn't even bother rolling for it.
Finally, Jarrett's player makes the targeting roll.  Selecting a center point about 5 paces behind and midway between the two goblins, the player adds the factors together.  Base 8, Rank 7, Attack Value 7, Difficulty 8 (base 2, +2 for Fatigue, +2 for movement at a run, +2 for the tough hides of the goblins).  ATC = 14.  The player rolls a 4, which is an Extraordinary Success.  The first goblin, who achieved a Marginal Success on his Passive Resistance Trial, will reduce that effect to a Superior Success - he'll only receive Major Wounds over every location on his body from the rear.  The second goblin, who failed his Passive Resistance Trial completely, gets hit with the full effect of the Shaping, taking Mortal Injuries over his entire body.
Jarrett focused intently on Shaping the fireball, trying very hard to ignore the two shouting goblins charging toward him.  He stretched out his hands above his head and concentrated the Mana between them, feeling it take form according to his will.  He grasped the Mana in his hand, almost feeling the heat of the flame as the Mana began to form actual fire, and then hurled the ball of fire out toward the target he had chosen, midway between and just behind the two goblins.  The ball of flame expanded as it flew, taking final form as an intense ball of flame, which could just now be seen by the two goblins.   Their eyes grew wide in their last seconds of consciousness as the ball exploded behind them with stunning fury, the flames washing over their bodies and burning everything they touched..  The goblins fell writhing on the ground as their flesh continued to smoke and curl even after the flames had subsided into nothing again. The grass and shrubs on the hillside were blackened and sooty from the flames.  One goblin continued to scream in pain for a few seconds, then joined his companion in unconsciousness.  Jarrett, low on Mana stores and still breathing heavily, decided he needed to get away from this spot, in case there were more goblins in the area.  And he needed to find a place to catch his breath and replenish his stores of Mana.  He set off across the hillside away from the goblins, heading back to the east and, hopefully, toward shelter.