The Alchemist

{2}, {t}: Put 1 Use counter on target non-potion artifact. It becomes a potion. When an ability of
that artifact would be activated or triggered, its controller must discard a Use counter or counter
that ability. Potion - When this artifact loses all of its
Use counters, sacrifice it at end of turn. It can't gain
or lose counters by other cards.
Whenever you sacrifice a potion, learn.