Soul of Windgrace + Waves of Aggression + Savage Ventmaw + Gruul Turf
Soul of Windgrace
Waves of Aggression
Savage Ventmaw
Gruul Turf
Infinite combat phasesInfinite landfall triggersInfinite magecraft triggersInfinite self-discard triggersInfinite storm countInfinite untap of most creatures you controlInfinite green manaInfinite red mana
How it works
Declare Savage Ventmaw and Soul of Windgrace as attackers.
When they attack, Savage Ventmaw and Soul of Windgrace trigger.
Resolve the Savage Ventmaw trigger, adding six mana that you will not lose this turn as steps and phases end.
Resolve the Soul of Windgrace trigger, returning Gruul Turf from your graveyard to the battlefield tapped.
When Gruul Turf enters, it triggers, returning itself from the battlefield to your hand.
In your next main phase, cast Waves of Aggression from your graveyard for its retrace cost by paying 3R/WR/W and discarding Gruul Turf, causing you to untap all creatures that attacked this turn, and to get an additional combat and main phase after this one.