Moritte of the Frost as a copy of the creature with persist.).
Steps
Activate
Evereth by sacrificing
Moritte of the Frost.
When
Moritte of the Frost dies, it triggers its persist ability, returning itself to the battlefield as a copy of the creature with persist with two +1/+1 counters and one -1/-1 counter on it.
Remove one +1/+1 counter and one -1/-1 counter from
Moritte of the Frost as a state-based action.
Resolve the activated ability from step 1.
Repeat.
Notes
If you have a way to kill
Evereth and ({1} magic symbol) ({BR} magic symbol) available, you can do so after putting a significant amount of +1/+1 counters on it to deal damage to each opponent using its second ability.
Results
Infinite +1/+1 counters on a creature.
Infinite creature ETB.
Infinite creature LTB.
Infinite creature sacrifice triggers.
Infinite death triggers.
Infinite damage.
Metadata
In 1 deck according to EDHREC.
Bracket Tag
This combo has been estimated to be Spicy (Bracket 3-4+).