The following is an example of Geoza Spirit Magic (Shamanism) in action.  The game mechanics will be interspersed with a narrative account of the events.
Jarrett saw the afternoon sun dropping fast 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 upslope 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 downslope 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'll have to try to take them out before they reach 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 Spirit Mage, 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 downslope, and decides to stand and fight.  Jarrett's relevant characteristics are as follows:
Charisma 8 Spirit Lore 8
Willpower 9 Spirit Capacity 16
Endurance 6 Meditation Asset 12
Communication 7
Perception 7 Bound Spirits Bear Spirit (1 service, SD 4)
Quickness 6 Greater Flame Spirit (1 service, SD 5)
SD = Summoning Difficulty (also counts as capacity requirement)
Additionally, Jarrett has a Spirit Ally (Rank 10), a Jann (powerful Elemental Spirit of the air).
Jarrett's Omnessence Expertises:
Conjuration 6 Energy 7
Creation 7 Organic 7
Destruction 5 Physical 7
Divination 8 Reality 4
Manipulation 7 Spirit 8
Transformation 8 Will 8
As can be seen from his ability levels, Jarrett is an experienced Spirit Mage, with a variety of options as to the kinds of effects he can create.  Jarrett's Option Point total for each Action Interval will be 8.
Jarrett leaned on his staff and opened his senses up to the Spirit Realms which exist above, around, below, and through all things.  He nudged Bear, curled and sleeping in a little spirit cave that Jarrett had prepared for him in his Aura.  "Come, brother bear.  I need you to fight for me.  Then you can return to your home."
Bear snuffled and wondered what there was to fight.  He smelled no corrupt spirits.  "No, fierce Bear, I need you to pick up this rock in the fixed-place, and hit that goblin being there, also in the fixed-place."  Jarrett stretched out his arm to point to the goblin clambering up the hillside toward them.
Jarrett decides to use one of the Spirits he already has bound to hurl a large rock at the nearest goblin.  He first spends 5 OPs making a Communication Trial to explain to the Bear Spirit what it is that he wants Bear to do.  Bear is a Naturae, a class of spirit based on physical animals or plants.  Like all Naturae, Bear's Material Comprehension  (3) is pretty good for a spirit, because they have a symbolic link to material things.   Material Comprehension is the base difficulty for the Communication Trial, so the lower the rating, the better the Spirit's comprehension is.  Jarrett's base for this trial is 3 (it's an attribute trial), and his rank is his Communication, 7.  The difficulty is 4, because Jarrett has a level of Fatigue from climbing hillsides all day.   Jarrett's Adjusted Trial Chance is 6 (3 + 7 - 4 = 6).  The player rolls a 4, acheiving a Complete Success.  Jarrett has successfully explained what exactly he wants Bear to do.
Jarrett's player tells the Mythguide that what he wants to do is have the Bear Spirit hurl that rock at the nearest goblin.  Jarrett proposes the following Manipulation/ Physical Spirit Paradigm: Hurl Rock
Scope Jarrett will have to expand the basic range to Sight, which is a Moderate level of Scope.  So the minimum cost for this Paradigm includes 6 points for Scope (base 2, plus 4 points, the minimum level for a Moderate effect).
Potency Just moving the rock is a minor alteration to the rock's physical state (currently at rest), which is a Moderate Effect (minimum 4).  Jarrett needs to really hurt the goblin, so he allocates another 10 points to Potency, which will give the hurled rock an attack value of 5 - a little better than the average longbow arrow.  Total of 14 points for Potency.
Intricacy Intricacy for this paradigm isn't bad - its only a Slight effect, Jarrett's player figures.
Temper Aspects Jarrett will need to Target the hurled rock, but that doesn't cost any Omnessence.   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 agrees with the assessment for this paradigm.  Jarrett's player has been doing this for a little while, knows the ARIA Paradigm System and the Spirit Origin, and he knows the way the Mythguide thinks.  The total cost for this paradigm will be 23 Omnessence.  A fairly easy effect, well under the limits of Jarrett's abilities - Jarrett has ratings of Manipulation 7 and Physical 7, and his Spirit Lore is an 8, so Jarrett has an effective Configuration Expertise of 7.  That means he can create an effect of up to 49 Omnessence (Manipulation 7 times Physical 7) - quite a bit more than this little paradigm requires.
Additionally, the Mythguide checks the Province of the Bear Spirit, and sees that it has a Configuration Might of 7 in Manipulation/Physical.  Ordinarily, that would mean a limit of 49 Omnessence, but since Jarrett had Bound the Bear Spirit to him, the Spirit's effective rating is reduced to 6 - a limit of 36 Omnessence, still well above what is required for this effect.
Bear growled and grew large, reaching down to the rock that lay in the physical world at Jarrett's feet.   The rock lifted and flew off toward the nearest goblin, hurtling through the air and hitting the goblin on the left leg just above the knee.  The goblin cried out in pain, but hobbled forward.
Bear, his service completed, lumbered off in the spirit world to look for a nice cave.  Or maybe a stream filled with leaping fish.  Yes, that would be good.
Hmm, Jarrett thought.   I'll need more than that to take out this goblin.  I wonder what other spirits there are around here that could help?
Jarrett spends the next OP channeling the power of Bear into the effect he wants, and makes an Effect Trial.   His base for the trial is 4 (half of his Charisma), and his rank is the average of his expertise in Manipulation (7), and Physical (7), which is 7.  The difficulty of the trial is the Affinity of the rock (3), modified by his fatigue (+1).  Jarrett's Adjusted Trial Chance is 7 (4 + 7 - 4 = 7).  The player rolls a 5, which is a Complete Success.
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 Charisma, 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 Winded, and that can affect his accuracy, so difficulty jumps to 3.   The Mythguide assesses the situation, and says that the goblin 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 14 - an almost certain success.  The player rolls a 0, followed by an 8, which results in a Complete Success.  The rock hits!
The Mythguide rolls a die for hit location, and announces that the rock has hit the goblin in the left leg, just above the knee, giving it a Wound and slowing it down somewhat.
Jarrett leaned against his staff and opened his senses to the Spirit Realms, seeking in the ephemeral otherworld for a spirit to aid him in his time of need.  He called upon his Spirit Ally the Jann, "Find me a Spirit of the Earth, one who can smash my enemy."  His Ally answered his call, finding a nearby spirit of the mountains, a small Troll.   Ahh, thought Jarrett, this will work.  Come, brother of the mountains, come aid your spirit brother Jarrett.
Jarrett reached out with his spirit and drew the Troll to him, smiling, hand outstretched to greet the Troll in brotherhood..  The Troll skipped across the hazy, shifting terrain of the Spirit world and stood before the mage.  "What do you need, spirit brother?" the small Troll asked Jarrett.  "Do you need a nice cave to sleep in?" 
Jarrett tries to summon a type of Earth Spirit, a Lesser Troll.  The Lesser Troll has a Summoning Difficulty of 4, which the Mythguide rules takes at least two entire Intervals to try to summon to Jarrett.  Jarrett makes a Meditation Trial to enter the Spirit World.  His Meditation Asset is 12, and the difficulty in this case is 4, the Mythguide says, because standing on the side of a hill with goblins climbing after you is not an ideal way to meditate, and Jarrett has a level of Fatigue from climbing hills all day, raising the difficulty to 5.  Jarrett's Spirit Ally can help him, adding half its rank to the ATC (+5) The player rolls a 1, followed by a 3, getting a Mythic Success!   Jarrett easily slips into the awareness of the Spirit Realms needed to summon a spirit to him, and locates a Lesser Troll in only one Action Interval.
Next, Jarrett makes a Charisma Trial.  His base is 3, and his rank is 8, giving him a Trial Asset of 11.   The base difficulty to summon a Lesser Troll is its Summoning Difficulty, a 4.   Jarrett's fatigue level doesn't affect his Charisma Trial - he's in the spirit world for the purposes of this trial, and being tired doesn't make him any less charismatic.  Also, Jarrett's Spirit Ally can help him on this trial as well (+5).   Jarrett's Adjusted Trial Chance is 12.  The player rolls an 8, achieving a Complete Success.  The Troll will grant him one service.
Jarrett doesn't have to Bind the Troll to use its services, and doing so would reduce its usefulness, so Jarrett doesn't Bind the Troll to him.
Jarrett then makes a Fatigue Trial at Difficulty 5 (same difficulty as the Meditation Trial he made earlier).  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 5, his Adjusted Trial Chance is 4 - not good.  And Jarrett's Spirit Ally can't help him with this one - at least, not directly.  Jarrett's player will have to roll well not to get another level of Fatigue from gathering that Omnessence - the player rolls, and gets a 3.  Whew!  Just under the number he needed.  Jarrett evades fatigue for now.
Note:  for the purposes of this example, the time necessary to summon a spirit was condensed to the minimum.  Although it is possible to find and summon a fairly powerful Spirit in only two Action Intervals, it would normally take much longer to find one and obtain its aid.   In this case, Jarrett was very lucky to find one so agreeable, so quickly.  Of course, having a powerful Jann as a Spirit Ally helps, as well.
"No, mountain-brother," Jarrett sent the spirit-thought to the Troll, "I just need you to pick up this rock and hit that goblin-being in the fixed-place with it, as fast and as hard as you can."  Will you do that for me, fierce Troll?
"Yes, that is an easy task, I shall do it for you now," the Troll said as it reached down to pick up the rock.  As the goblin hobbles closer, the Troll hits the wounded goblin with incredible speed, smashing the rock 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.
Note:  The "fixed-place" that Jarrett is referring to is one way of referring to the material world to a Spirit.  Spirit's commonly think of their "otherworld," the physical world, as being basically fixed and unchanging in comparison to their own.
This effect is basically the same as the last one, with a massive increase in Potency.  Jarrett's player decides to allocate 30 Omnessence to Potency, for an Attack Value of 15.  This rock is going to smash that goblin flat!  The total cost for this paradigm will be 43 Omnessence (6 for Scope, 34 for Potency, and 3 for Intricacy).
The Mythguide checks the Province of a Lesser Troll, and sees that it has a Configuration Might of 8 in Manipulation/Physical, more than enough to handle this effect.
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 10 points 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 23.   He rolls a 6, 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 upslope and were now approaching very quickly across the hillside.  Have to take out both of them at the same time, he thought.   Another rock won't do it.  Jarrett reached out one more time to the Spirit Realms, this time feeling for the presence of the Flame Spirit he has Bound to him.   "Come, brother fire," Jarrett thinks to the flickering Spirit, "Aid me now and you will go free.  I want you to burn those two goblin-beings in the fixed-place, and cover them with your hot flames!"
"Yesssss," hissed the Flame Spirit, "I will burn them with fire from the heart of the furnaces of my home."  As Jarrett pointed to the spot midway between and just behind the two goblins, where he wanted the effect to center, the Flame Spirit flashed to that location and manifested a huge ball of fire into the material world, using Jarrett's will as a channel for its power.
Jarrett doesn't have time for anything but to call upon his remaining Bound Spirit, a Greater Flame Spirit, and ask it to burn the goblins.  The effect Jarrett's player has in mind will be a Creation/Energy Spirit Paradigm:  Fireball.  He's done this before, so he knows it will look something like this:
Scope Jarrett will have to expand the basic range to Sight, which is a Moderate level of Scope, at least 4 points.  Additionally, this will be an Area effect, so that's another Moderate Scope increase, and gives him a basic radius of effect of (6 - Material Comprehension paces), or   2 paces.  Figure 10 points total for Scope.
Potency Jarrett needs a powerful effect for this one, he won't have time to try again.  The player allocates 24 points to Potency, which will yield an Attack Value of 12.
Intricacy Intricacy is a little higher for this paradigm.  Jarrett needs the fire to have elemental effects (i.e. it burns like fire, not just energy that looks like fire), which is a Moderate effect.  Jarrett allocates 8 points to Intricacy.
Temper Aspects Jarrett will need to Target the fireball, but that doesn't cost any Omnessence, just a Targeting Trial.   Also, he puts 4 points into the Widen Temper Aspect, which increases the radius of effect for this Shaping to 10 paces in radius (Variation Facility for Spirit Widen Aspect is 1 - for each point of Omnessence allocated to Widen, the area is increased by the base increment.  The base is 2 paces, so each point adds 2 paces.  2 + (4 * 2) = 10 paces total radius).
Total cost for this effect is 46 points of Omnessence.  That's just under Jarrett's limit for a Creation Energy paradigm.  Although his Spirit Lore is 8 (max 64 points), his expertises in Creation (7) and Energy (7) give him a limit of 49 points of Omnessence, so he's limited by his relative lack of experience in Creation/Energy effects.  Remember Geoza handles Omnessence Limits slightly differently than in ARIA - instead of averaging the ranks, and then squaring the result, just multiply the ranks together directly.  This gives a smoother progression of ability than the standard ARIA method.
Jarrett spends 5 OPs in this Interval communicating the intent for his fireball effect to the Spirit, then spends 1 OP to Channel the effect.  Jarrett's player rolls the Effect Trial.   Base = 4, Rank = 7 (average of Creation / Energy, limited by Spirit 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 effect 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.  Spirit 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' Affinity.  Pretty average - just like the rock.  Of course, that base Difficulty is increased by Jarrett's Fatigue (+1), so final Difficulty for this Effect Trial is 4.  4+7-4 = 7.  Jarrett's Adjusted Trial Chance is 7.  The player rolls a 4, which results in a Complete Success for this effect.
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 Spirit 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 Spirit effect is the Effect Might of the paradigm.  The total of potency and intricacy is 32 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 resist this effect even partially.  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.
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 12, Difficulty 7 (base 2, +1 for Fatigue, +2 for movement at a run, +2 for the tough hides of the goblins).  ATC = 20.  The player rolls a 6, 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 fireball, taking Mortal Injuries over his entire body.
Jarrett focused intently on Channeling the fireball, trying very hard to ignore the two shouting goblins charging toward him.  The ball of flame expanded as it flew, the Flame Spirit 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, 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 find new Spirits to Bind to his service.  He set off across the hillside away from the goblins, heading back to the east and, hopefully, towards shelter.