Cast Clever Impersonator by paying its mana cost. Choose to have it enter the battlefield as a copy of Rakdos Joins Up.
Put Clever Impersonator into your graveyard due to the legend rule.
Clever Impersonator's first ability and second ability trigger, along with Rakdos Joins Up's second ability.
Resolve Clever Impersonator's second trigger and Rakdos Joins Up's trigger, dealing damage to target opponent and causing you to gain that much life.
Resolve Clever Impersonator'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.
Repeat from step 2.

Infinite creature LTB

Infinite creature ETB

Infinite death triggers

Infinite damage

Rakdos Joins Up

Clever Impersonator

Cast Clone by paying its mana cost. Choose to have it enter the battlefield as a copy of Rakdos Joins Up.
Put Clone into your graveyard due to the legend rule.
Clone's first ability and second ability trigger, along with Rakdos Joins Up's second ability.
Resolve Clone's second trigger and Rakdos Joins Up's trigger, dealing damage to target opponent.
Resolve Clone'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.
Repeat from step 2.

Starfield of Nyx

Clone

Activate Zur by paying {1}{W}, causing Rakdos Joins Up to become a creature.
Cast Glasspool Mimic by paying its mana cost. Choose to have it enter the battlefield as a copy of Rakdos Joins Up.
Put Glasspool Mimic into your graveyard due to the legend rule.
Glasspool Mimic's first ability and second ability trigger, along with Rakdos Joins Up's second ability.
Resolve Glasspool Mimic's second trigger and Rakdos Joins Up's trigger, dealing damage to target opponent and causing you to gain that much life.
Resolve Glasspool Mimic'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.
Repeat from step 3.

Infinite lifegain triggers

Infinite lifegain

Zur, Eternal Schemer

Glasspool Mimic // Glasspool Shore

Cast Rakdos Joins Up by paying {3}{B}{R}.
When Rakdos Joins Up enters the battlefield, its first ability triggers.
Holding priority, activate Auratog by sacrificing Rakdos Joins Up.
Resolve the Rakdos Joins Up ability, returning Archon of Falling Stars from your graveyard to the battlefield with two +1/+1 counters on it.
When Archon of Falling Stars enters the battlefield, it triggers.
Holding priority, activate Bloodthrone Vampire by sacrificing Archon of Falling Stars.
Resolve the Archon of Falling Stars ability, returning Rakdos Joins Up from your graveyard to the battlefield.
Repeat from step 2.

Infinite creature sacrifice triggers

Infinitely large creature until end of turn

Archon of Falling Stars

Auratog

Bloodthrone Vampire

Cast Omni-Changeling by paying its mana cost. Choose to have it enter the battlefield as a copy of Rakdos Joins Up.
Put Omni-Changeling into your graveyard due to the legend rule.
Omni-Changeling's first ability and second ability trigger, along with Rakdos Joins Up's second ability.
Resolve Omni-Changeling's second trigger and Rakdos Joins Up's trigger, dealing damage to target opponent.
Resolve Omni-Changeling'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.
Repeat from step 2.

Combos with "Rakdos Joins Up"