Yenna, Redtooth Regent + Second Wind + Thaumatog

Yenna, Redtooth Regent

Second Wind

Thaumatog

How it works

1. Activate the mana-producing creature by tapping it, adding at least 2.
2. Activate Yenna by paying 2 and tapping it, creating a token copy of Second Wind attached to the mana-producing creature, then untapping Yenna and causing you to scry 2.
3. Activate the Second Wind token's second ability by tapping it, untapping the mana-producing creature.
4. Activate Thaumatog by sacrificing the Second Wind token.
5. Repeat.