Isle of Vesuva

Every creature that walks into play arrives twice while this plane is active, and the symmetry is the whole joke: your opponents get their doubled bodies too, so the board bloats in every direction until someone finds an outlet. The second ability is that outlet, and it reads like a punchline written specifically for the first. Because copies share a name, rolling into the chaos trigger and pointing it at any creature wipes every creature sharing that name at once: the original, its token twin, and every other copy floating around the table. A plane that manufactures duplicates in one clause and then punishes duplication in the next is doing something knowingly perverse with the shared-name rule that most cards treat as an afterthought. The copy trigger fires on nontoken creatures only, which keeps the loop from feeding itself infinitely, but it makes every real creature you play a decision about how badly you want to hand your opponents free bodies. This is Planechase design at its most gleefully chaotic: not a static buff or a mana engine, but a rules environment that turns the token-copy interaction and the name-matching destruction clause into two halves of a single trap, where the value you accrue from doubling is exactly the liability the chaos roll can turn against you.