Resolve the persist ability, returning it from your graveyard to the battlefield with a -1/-1 counter on it and at least one +1/+1 counter on it due to
Gorma.
Remove a -1/-1 counter and a +1/+1 counter from that creature as a state-based action.
Resolve the
Spawning Pit ability.
Repeat.
Results
Infinite +1/+1 counters on a creature.
Infinite charge counters on a permanent.
Infinite creature ETB.
Infinite creature LTB.
Infinite creature sacrifice triggers.
Infinite death triggers.
Metadata
In 428 decks according to EDHREC.
Bracket Tag
This combo has been estimated to be Oddball (Bracket 2-3+).