Shadow Kin

Clone effects usually ask you to point at a creature already on the battlefield; this one turns the mill it forces into a menu. At the start of your upkeep, every player grinds three cards, and if a creature surfaces from among them, this Shapeshifter can exile it and become a copy on the spot. The result is a body whose identity is rewritten each of your turns, drawing from whatever the collective libraries happen to spit up rather than from a target you can survey and evaluate in advance. That randomness is the price the design pays for the flexibility: you don't choose which creatures are on offer, only whether to take one of the ones that appeared, and because the copied ability includes itself, the transformation can keep happening turn after turn. Flash is the quiet enabler, letting it land at the end of an opponent's turn so its first trigger fires on your very next upkeep instead of after a full lap of the table. The mill hits every player, so the fuel it feeds on is shared rather than self-inflicted. The design tension is that the card is only ever as strong as the aggregate quality of creatures across everyone's decks: it converts a symmetrical grind that all players participate in into a private, repeatable shapeshift, and what it becomes is never guaranteed to be worth the exile.