Infinite creature LTBInfinite creature ETBInfinite creature sacrifice triggersInfinite death triggersInfinite lifegain triggersInfinite lifegainInfinite combat phasesInfinite untap of creatures you controlInfinite mana creatures you control can produceInfinite +1/+1 counters on a creature
How it works
Cast All-Out Assault by paying 2.
When All-Out Assault enters the battlefield, it triggers, causing you to get an additional combat and main phase after this one.
Move to your extra combat phase. All-Out Assault triggers, untapping each creature you control.
Declare Carmen as an attacker, triggering its second ability, returning Leonin Relic-Warder form your graveyard to the battlefield.
When Leonin Relic-Warder enters the battlefield, its first ability triggers, exiling All-Out Assault.
Move to your postcombat main phase, and activate Bloodflow Connoisseur by sacrificing Leonin Relic-Warder.
When Leonin Relic-Warder dies, its second ability and Carmen's first ability trigger.
Resolve the Carmen trigger, putting a +1/+1 counter on it and causing you to gain 1 life.
Resolve the Leonin Relic-Warder trigger, returning All-Out Assault from exile to the battlefield.
When All-Out Assault enters the battlefield, it triggers, causing you to get an additional combat and main phase after this one.