Elemental Mastery + Black Carriage
Elemental Mastery must be on the battlefield. Black Carriage must be on the battlefield. Elemental Mastery attached to Black Carriage.
- During your upkeep, activate Black Carriage by tapping it, creating at least four 1/1 Elemental creature tokens.
- Activate Black Carriage by paying and sacrificing an Elemental token, untapping Black Carriage.
Infinite creature tokens with haste. Infinite ETB.