Kalain, Reclusive Painter
Legendary Creature — Human Elf Bard
When Kalain, Reclusive Painter enters the battlefield, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.") Other creatures you control enter the battlefield with an additional +1/+1 counter on them for each mana from a Treasure spent to cast them.