Thran Dynamo + Umbral Mantle + Karn's Touch

Thran Dynamo

Umbral Mantle

Karn's Touch

How it works

1. Cast Karn's Touch by paying , targeting Thran Dynamo.
2. Activate Umbral Mantle's equip ability by paying 0, attaching it to the Thran Dynamo.
3. Activate Thran Dynamo by tapping it, adding CCC.
4. Activate Umbral Mantle by paying 3 and untapping it, giving itself +2/+2 until end of turn.
5. Repeat.