Activate Supportive Parents by tapping two untapped colored legendary creatures, adding one mana of any color.
Cast any colored legendary creature for its web-slinging cost by paying {0} due to Morophon and returning one of the creatures tapped in step 1 from the battlefield to your hand.
Repeat step 2 one additional time.
Repeat from step 1.

Infinite creature ETB

Infinite creature LTB

Infinite colored mana

Infinite storm count

Morophon, the Boundless

Peter Parker // Amazing Spider-Man

Supportive Parents

Activate Selvala by paying {G} and tapping it, adding at least {1}{G}{G}{W}{U}.
Activate Aura of Dominion by paying {1} and tapping another nontoken colored legendary creature you control, untapping Selvala.
Cast a legendary creature from your hand for its web-slinging cost by paying {G}{W}{U} and returning the creature tapped in step 2 from the battlefield to your hand.
Repeat.

Selvala, Heart of the Wilds

Aura of Dominion

Activate Ashnod's Altar by sacrificing Peter Parker, adding {C}{C}.
When Peter Parker dies, Nim Deathmantle triggers, causing you to pay {4} to return Peter Parker from your graveyard to the battlefield and attach Nim Deathmantle to it.
When Peter Parker enters, it triggers, creating a creature token.
Activate Ashnod's Altar by sacrificing a creature token, adding {C}{C}.
Repeat.

Infinite creature sacrifice triggers

Infinite death triggers

Nim Deathmantle

Ashnod's Altar

Combos with "Peter Parker // Amazing Spider-Man"