You may spend mana as though it were mana of any color to activate abilities of creatures you control. Creatures you control with +1/+1 counters on them have all activated abilities of all creature cards exiled with Agatha's Soul Cauldron. {T}: Exile target card from a graveyard. When a creature card is exiled this way, put a +1/+1 counter on target creature you control.

Search target opponent's library for an artifact card and put that card onto the battlefield under your control. Then that player shuffles.

{T}: Target artifact creature's controller sacrifices it. That player may search their library for a noncreature artifact card, put it onto the battlefield, then shuffle.

Search your library for an artifact card, reveal it, put it into your hand, then shuffle.

Vigilance When this creature enters, you may search your library for an artifact card, reveal it, then shuffle. Put that card into your hand if you control an Assassin. Otherwise, put that card on top of your library.