Tinker Toy Smelting Room

({t}: Add {u}, {r},or {w} to your mana pool)
As Tinker Toy Smelting Room enters the battlefield, you may pay 3 life. If you don't,
it enters the battlefield tapped.
"Molds, Blueprints, Tools, and Circuitry litter every surface of this place, it may seem like a pile of junk at first, but all of these things have a very special
purpose in making every one of my children unique".
- Ezex, The Tinkerer