Mikaeus, the Unhallowed | Blasting Station (and one other card)

Persist Creature

Cards

Activate
Blasting Station by tapping it and sacrificing the creature with persist.
When that creature dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
When it enters,
Blasting Station triggers, untapping itself.
Resolve the
Blasting Station ability from step 1, dealing 1 damage.
Activate
Blasting Station by tapping it and sacrificing the Persist Creature.
When the Persist Creature dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
When it enters,
Blasting Station triggers, untapping itself.
Resolve the
Blasting Station ability from step 5, dealing 1 damage.
Repeat.

This combo has been estimated to be Spicy (Bracket 3-4+).