All 31 Combos with Arcbound Fiend

Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight + Arcbound Ravager + Arcbound Fiend

Other: Infinite artifact ETB, Infinite artifact LTB, Infinite artifact sacrifice triggers, Infinite creature LTB, Infinite creature ETB, Infinite creature sacrifice triggers, Infinite death triggers, Infinite +1/+1 counters on a creature, Infinite +1/+1 counters on certain creatures, Draw the game

Activate Arcbound Ravager by sacrificing Arcbound Fiend. When Arcbound Fiend dies, its modular ability and persist ability trigger. Resolve the modular trigger, putting Arcbound Fiend's +1/+1 counters on another artifact creature. Resolve the persist trigger, returning Arcbound Fiend from your graveyard to the battlefield. It will not have a -1/-1 counter on it due to its modular ability. Resolve the Arcbound Ravager ability. Repeat.