Cryptex (Promo Pack) [Murders at Karlov Manor Promos]

T, Collect evidence 3: Add one mana of any color. Put an unlock counter on Cryptex. (To collect evidence 3, exile cards with total mana value 3 or greater from your graveyard.)

Sacrifice Cryptex: Surveil 3, then draw three cards. Activate only if Cryptex has five or more unlock counters on it.