Purifier

Purifier is a shared event (appearing in Acts 1-3) that offers free card removal — you may remove one card of your choice from your deck at no cost. There is no HP or gold cost associated with this event. The removed card is permanently gone from your deck for the remainder of the run.

Purifier is one of the best events in the game. Free card removal is consistently valuable at any point in a run, as a smaller, more focused deck performs more reliably than a large, bloated one. Using Purifier to remove Strikes, Defends, or Curses is almost always correct. In extreme cases where your deck is already perfectly lean, the Purifier can be skipped, but this is rare. The event is particularly valuable in Act 1 when the deck is still cluttered with starting cards.