Haunted Crossroads by paying ({B} magic symbol) , putting
Priest of Gix from your graveyard onto the top of your library.
Resolve the
Rakdos trigger, causing you to exile the top three cards of your library with the ability to play them until your next end step.
Resolve the
Evereth ability from step 1.
Cast
Priest of Gix from exile by paying at most ({2} magic symbol) .
When
Priest of Gix enters the battlefield, it triggers, adding ({B} magic symbol) ({B} magic symbol) ({B} magic symbol) .
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
Exile your library with the ability to play the exiled cards until your next end step.
Infinite +1/+1 counters on a creature.
Infinite black mana.
Infinite creature ETB.
Infinite creature LTB.
Infinite creature sacrifice triggers.
Infinite death triggers.
Infinite storm count.
Infinite damage.
Metadata
In 0 decks according to EDHREC.
Bracket Tag
This combo has been estimated to be Exhibition (Bracket 1+).