Blim, Comedic Genius

The control-change effect of Blim's ability lasts indefinitely. It doesn't wear off during the cleanup step, and it doesn't expire if Blim leaves the battlefield. In a multiplayer game, it does expire if the current controller leaves the game.

If the target permanent you control is an illegal target by the time Blim's ability tries to resolve, the ability doesn't resolve. The other player doesn't gain control of your permanent, and no one loses life or discards cards.

Players lose life and discard cards for all permanents they control but don't own, not just the ones they received from you.