Mutate (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)
Flying, trample
Whenever this creature mutates, exile cards from the top of your library until you exile a nonland permanent card. Put that card onto the battlefield or into your hand.
Cheat huge nonland permanents onto the battlefield by repeatedly mutating Illuna over your non-Human creatures, hitting the trigger to dig until you flip a permanent and put it directly into play for free. You ramp into Illuna, stack cheap mutate fodder, then chain mutate effects (often returning Illuna with bounce or recasting it) to snowball value and close with a fat flying/trampling stack.
Free permanents off every mutate trigger, including bombs you'd never hardcast
Mutate stacks abilities, building a single resilient threat with evasion (flying, trample)
Heavy top-end payoff makes ramp and big-mana strategies extremely rewarding
Temur colors give access to the best card advantage, ramp, and interaction
The mutate trigger is random — you can flip a low-impact permanent or whiff into lands
Removing or bouncing Illuna mid-stack can strand your fodder and tempo
Needs non-Human creatures already in play to mutate cheaply, so it can stall early
Putting all value on one stacked creature is vulnerable to a single exile or wrath
Commander tax and repeated recasting strain mana if Illuna keeps dying
Premium blue interaction that protects your stacked threat and clears blockers for a lethal swing.
Lean into high-density, high-impact nonland permanents so every mutate trigger matters — pack your deck with bombs and few weak permanents, and minimize lands you can afford to skip. Add cheap, recurring mutate fodder (Brokkos, Pollywog Symbiote, Migratory Greathorn) plus ways to bounce or re-cheat Illuna, then round out with blue protection (Heroic Intervention, counterspells) so your stacked threat survives. Top-end ramp like Cultivate, Three Visits, and mana rocks accelerates you to the multi-mutate turns that win.