Blightbeetle | Mikaeus, the Unhallowed | Goblin Sharpshooter (and one other card)

Cards

All permanents on the battlefield (
Goblin Sharpshooter without summoning sickness and
Blim without summoning sickness and cannot be blocked by an opponent).

You have a way to give
Goblin Sharpshooter deathtouch.
You control an additional nontoken non-Human creature that does not have indestructible or protection from red.

Give control of
Blightbeetle to an opponent, if needed. Also, give
Goblin Sharpshooter deathtouch, if needed.
Activate
Goblin Sharpshooter by tapping it, dealing 1 damage to the additional creature and destroying it due to
Goblin Sharpshooter's deathtouch.
When the creature dies, its undying ability and
Goblin Sharpshooter trigger.
Resolve the creature's undying trigger, returning it from your graveyard to the battlefield without a +1/+1 counter on it due to
Blightbeetle.
Resolve the
Goblin Sharpshooter trigger, untapping it.
Repeat from step 2.

This combo has been estimated to be Exhibition (Bracket 1+).