All permanents on the battlefield (Undying Creature without a +1/+1 counter on it).
Easy Prerequisites
An opponent controls a creature.
Mana Needed
({4} magic symbol) ({U} magic symbol) available.
Steps
Donate
Blightbeetle to an opponent.
Activate
Goblin Bombardment by sacrificing the Undying Creature.
When the Undying Creature dies, its undying ability triggers, returning itself from your graveyard to the battlefield without a +1/+1 counter on it due to
Blightbeetle.
Resolve the
Goblin Bombardment ability.
Repeat from step 2.
Results
Infinite ETB.
Infinite LTB.
Infinite damage.
Infinite death triggers.
Infinite sacrifice triggers.
Metadata
In 0 decks according to EDHREC.
Bracket Tag
This combo has been estimated to be Exhibition (Bracket 1+).