Ren

When you cast an instant or sorcery card, place
a +1/+1 counter on Ren. Your enchantments
cost {1} less for each +1/+1 counter on Ren.

You can remove {x} +1/+1 counters from Ren to duplicate another creature on the battlefield
of {x} mana cost.
"I'm just a very aggravating person"
— Ren