Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight + Phantom Train + Ambitious Aetherborn
Infinite LTB, Infinite ETB, Infinite sacrifice triggers, Infinite death triggers, Infinite +1/+1 counters on a creature
Activate Phantom Train by sacrificing Ambitious Aetherborn.
When Ambitious Aetherborn dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
When Ambitious Aetherborn enters, its fabricate ability triggers, putting a +1/+1 counter on it.
Resolve the Phantom Train ability.
Repeat.
Component Cards
How It Works
Activate Phantom Train by sacrificing Ambitious Aetherborn.
When Ambitious Aetherborn dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
When Ambitious Aetherborn enters, its fabricate ability triggers, putting a +1/+1 counter on it.
Resolve the Phantom Train ability.
Repeat.