Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight + Grim Poppet + Ashnod's Altar
Infinite LTB, Infinite ETB, Infinite sacrifice triggers, Infinite death triggers, Infinite colorless mana, Destroy each creature that enters the battlefield under an opponent's control, Destroy any number of creatures, Infinite -1/-1 counters, Lock
If Grim Poppet has any -1/-1 counters on it, activate it by removing a -1/-1 counter from it.
Repeat step 1 as necessary until Grim Poppet has no -1/-1 counters on it.
Activate Ashnod's Altar by sacrificing Grim Poppet.
When Grim Poppet dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
Repeat.
Resolve all Grim Poppet abilities, putting infinite -1/-1 counters on any number of creatures.
Component Cards
How It Works
If Grim Poppet has any -1/-1 counters on it, activate it by removing a -1/-1 counter from it.
Repeat step 1 as necessary until Grim Poppet has no -1/-1 counters on it.
Activate Ashnod's Altar by sacrificing Grim Poppet.
When Grim Poppet dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
Repeat.
Resolve all Grim Poppet abilities, putting infinite -1/-1 counters on any number of creatures.