: Exile target card from a graveyard. When a creature card is exiled this way, put a +1/+1 counter on target creature you control.
: Put two +1/+1 counters on Argothian Sprite." If you controlled a Callous Sell-Sword with a +1/+1 counter on it, you'd treat it as though it had the ability "Agatha's Soul Cauldron turns creature cards in graveyards into an ability collection for your counter-bearing creatures. Its tap ability exiles a card from a graveyard; if that card is a creature, a follow-up trigger can place a +1/+1 counter on one of your creatures. Creatures you control with those counters gain the activated abilities of creature cards exiled with that Cauldron.
The setup therefore has two sides: exile an ability worth borrowing and make sure a suitable creature has a counter. Walking Ballista can provide its damage ability, while other creatures offer untaps, card selection, or mana abilities. The Cauldron also lets you spend mana as though it were any color to activate your creatures' abilities, helping pay colored requirements on borrowed text.
It grants activated abilities, not every ability on the exiled card. Entry triggers, static bonuses, and death triggers do not transfer merely because the creature card was exiled. Tap-symbol abilities still follow summoning-sickness rules, and all other costs need to be paid.
The graveyard targeting also offers disruption, since the first ability can exile any card even when no counter reward follows. If the Cauldron leaves and returns, it is a new object and does not simply retain the old collection of exiled abilities.
Choose borrowed abilities that solve a specific problem or connect to an intentional combo. A deck with natural +1/+1 counter production can spread access across several creatures, making the artifact useful beyond one vulnerable carrier. The most productive setups have both an affordable activation and a clear outlet for the resource it creates.
