Combat Celebrant + Adarkar Valkyrie + Anger + Ashnod's Altar

Combat Celebrant

Adarkar Valkyrie

Anger

Ashnod's Altar

How it works

1. Activate Adarkar Valkyrie by tapping it, targeting Combat Celebrant.
2. Declare Combat Celebrant as an attacker, choosing to exert it as it attacks.
3. Combat Celebrant triggers, untapping all other creatures you control and causing you to get an additional combat phase after this one.
4. Activate Ashnod's Altar by sacrificing Combat Celebrant, adding CC.
5. Combat Celebrant dies, triggering Adarkar Valkyrie, returning Combat Celebrant from your graveyard to the battlefield.
6. Repeat.