Cayth, Famed Mechanist + Mana Echoes + Sparring Mummy

Cayth, Famed Mechanist

Mana Echoes

Sparring Mummy

How it works

1. Activate Cayth by paying 2 and tapping it, creating a copy of the Sparring Mummy token.
2. When the Sparring Mummy token enters the battlefield, it and Mana Echoes trigger.
3. Resolve the Sparring Mummy trigger, untapping Cayth
4. Resolve the Mana Echoes trigger, adding C for each creature you control that shares a type with the Sparring Mummy token.
5. Repeat.