What's the most cards I can control at once in a game, allowing the cooperation of all players, but best if not?
A.k.a as many cards that can be affected by "X you control" effects like Serra's Blessing.
A.k.a not about the number of cards I start with or can take with me at the end of the game.
That gives a player control of all the cards that's possible to be played in a game.
But are there ways beyond that? Like my hypothetical "turning an infinite number of tokens into 'cards' a.k.a 'things that will persist beyond death'", is currently impossible, but are there other ways?
With everyone's cooperation, I suppose the "you own" part on something like Spawnsire of Ulamog, can be waived and just allow any kind of Eldrazi or other cards, via Artificial Evolution, to be brought in, regardless of ownership?
Without such waiving, would be best, but that's just a hope.