If EVP is depleted, the evolution state cannot be maintained even in battles
There are many prior examples of such thematic reliance, often ending in gimmicky unplayableness
Once per turn, during the End Phase, if this card was Special Summoned this turn: Return it to the hand, and if you do, Special Summon 2 "Shinobird Tokens" (Winged Beast-Type/WIND/Level 4/ATK 1500/DEF 1500)
It is also why black is the most common colour alongside blue in legacy and vintage where you need to have some interaction with spells and their potential to be cast so as to not get run over by broken things
Its other card types (such as artifact) and supertypes (such as legendary), if any, will remain unchanged
If youre running a deck that can get quite a few monsters out at once, then Id recommend putting this card straight into the extra deck