Clarisse, Stealer of Secrets

Clarisse, Stealer of Secrets, can't be blocked.
Whenever Clarisse, Stealer of Secrets deals
combat damage to a player, that player reveals
their hand. You choose a card from among
them and exile it. For as long as it remains
exiled, you may cast it, and you may use mana
as though it were mana of any colour to do so.
If you control five or more permanents you don't
own, you win the game.