Columbo, Case Solver

Whenever Columbo, Case Solver enters the battlefield, blocks, or is under your control at the beginning of your end step, create a clue token.

Sacrifice a Clue token: Tap target permanent
{3}, Sacrifice 3 clue tokens: Exile target permanent. If the exiled permanent was an opponent's commander, return it to its owner's graveyard when Columbo, Case solver leaves the battlefield.