Soul of Windgrace can attack without taking damage.
Savage Ventmaw can attack without taking damage.
Steps
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
Oboro, Palace in the Clouds from your graveyard to the battlefield tapped.
Activate the last ability of
Oboro, Palace in the Clouds by paying , returning it from the battlefield to your hand.
In your next main phase, cast
Waves of Aggression from your graveyard for its retrace cost by paying and discarding
Oboro, Palace in the Clouds, causing you to untap all creatures that attacked this turn, and to get an additional combat and main phase after this one.
Repeat.
Results
Infinite combat phases.
Infinite landfall triggers.
Infinite magecraft triggers.
Infinite self-discard triggers.
Infinite storm count.
Infinite untap of most creatures you control.
Metadata
Bracket tag
ExhibitionBracket 1+
For any deck
1
2
3
4
5
1 · Exhibition5 · cEDH
Bracket tags are estimated from the cards and results of each combo, as a guideline rather than a strict classification.