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 LTB

Infinite ETB

Infinite death triggers

Infinite damage

Rakdos Joins Up

Clever Impersonator

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

Phyrexian Metamorph

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

Opalescence

Mirror Image

Cast Rakdos Joins Up by paying {3}{B}{R}.
When Rakdos Joins Up enters the battlefield, its first ability triggers.
Holding priority, activate Faith Healer 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 Thermopod 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 sacrifice triggers

Infinite red mana

Archon of Falling Stars

Thermopod

Faith Healer

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