The 'magus' idea you mentioned gave me the idea of a series...
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magus that perhaps heals you for every creature played.
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magus that buffs the attack power of any friendly creature summoned.
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magus that affects the opponent, delaying their creatures.
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magus that weakens the attack power of any enemy creatures played.
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magus that boosts the HP of any friendly creature played.
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magus that reduces the Max HP of any enemy creature played.
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magus might require a quanta upkeep due to the first power that comes to mind, granting immortality to any creature played.
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magus could grant the passive 'airborne' to friendly creature played.
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magus might scramble a creature's skill cost, making it cost a random elemental quanta, including rainbow.
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magus could grant momentum to friendly creatures, at a quanta upkeep price.
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magus either grants biolumence, or perhaps heals all creatures when a creature is played.
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magus could 'refund' you 1 quanta of that creature's element when played, essentially cutting down on the cost of summoning creatures, in a sense.
quanta upkeep seems to also be a potential balancing factor, and this list probably could more or less be straight converted into permanent auras.
Yet another idea, one I kinda like, is this effect as a spell, that provides this buff to the next creature summoned. I propose that the permanent, creature, and spell buff ideas be appropriately scattered throughout the elements, so for example,
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's effect becomes a spell, alongside quintessance, but working instantly, while
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's effect, due to it's situational nature, be a permanent.
Any ideas you'd like to add to this list OldTrees?