Rakdos Joins Up + Opalescence + Altered Ego

Rakdos Joins Up

Opalescence

Altered Ego

How it works

1. Cast Altered Ego by paying its mana cost. Choose to have it enter the battlefield as a copy of Rakdos Joins Up.
2. Put Altered Ego into your graveyard due to the legend rule.
3. Altered Ego's first ability and second ability trigger, along with Rakdos Joins Up's second ability.
4. Resolve Altered Ego's second trigger and Rakdos Joins Up's trigger, dealing damage to target opponent.
5. Resolve Altered Ego's first trigger, returning it from your graveyard to the battlefield with two +1/+1 counters on it as a copy of Rakdos Joins Up.
6. Repeat from step 2.

This loop relies on turning enchantments into creatures with Opalescence, allowing Altered Ego to enter the battlefield as a copy of the enchantment Rakdos Joins Up. Because multiple copies of a legendary permanent trigger the legend rule, the newly copied Altered Ego instantly dies, which triggers its own ability to return itself from the graveyard while simultaneously using Rakdos Joins Up's second ability to blast an opponent with damage. By repeatedly looping this entry and death cycle, you continuously retrigger the original Rakdos Joins Up alongside the recursion of Altered Ego to deal infinite damage.