Mishra, The Forgotten

All artifacts, (including opponents') can only be
cast using {u} or {b} mana.
You may cast Historic spells (Legendary, Artifact
or Saga) for {3}
{1}{u}{b}: Create a Saga Token and put it into play:
1: Create a 3/3 colorless, flying thopter token .
2: Target opponent gains control of target artifact
3: Destroy target artifact, it deals damage equal to
it's casting cost to it's current controller.