Cast Marang River Regent by paying {0} due to Dracogenesis.
When Marang River Regent enters the battlefield, it and Miirym trigger.
Resolve the Marang River Regent trigger, returning up to two other nonland permanents to their owners' hands.
Resolve the Miirym trigger, creating a token copy of Marang River Regent.
When the Marang River Regent token enters the battlefield, it triggers, returning the nontoken Marang River Regent and up to one other nonland permanent to their owners' hands.
Repeat.

Return all nonland permanents opponents control to their owner's hand

Infinite creature LTB

Infinite creature ETB

Infinite storm count

Infinite creature tokens

Miirym, Sentinel Wyrm

Dracogenesis

Marang River Regent // Coil and Catch

Cast the Dragon in your hand without paying its mana cost.
When the Dragon enters the battlefield, Cloudstone Curio triggers, returning another nontoken Dragon from the battlefield to your hand.
Repeat.

Dragon Creature

Cloudstone Curio

Cast the Dragon in your hand without paying its mana cost.
When the Dragon enters the battlefield, Cloudstone Curio triggers if the Dragon isn't an artifact and Lathliss triggers.
Resolve the Cloudstone Curio trigger, if applicable, choosing to return nothing.
Resolve the Lathliss trigger, creating a 5/5 Dragon creature token.
When the Dragon token enters the battlefield, Cloudstone Curio triggers, returning the Dragon cast in step 1 from the battlefield to your hand.
Repeat.

Lathliss, Dragon Queen

Cast the Dragon in your hand without paying its mana cost.
When the Dragon enters the battlefield, Cloudstone Curio triggers if the Dragon isn't an artifact and Miirym triggers.
Resolve the Cloudstone Curio trigger, if applicable, choosing to return nothing.
Resolve the Miirym trigger, creating a token copy of the Dragon that isn't legendary if the Dragon was legendary.
When the Dragon token enters the battlefield, Cloudstone Curio triggers, returning the Dragon cast in step 1 from the battlefield to your hand.
Repeat.

Infinite copies of most nontoken Dragons you control

Cast Tiamat either from your hand or from the command zone without paying its mana cost plus commander tax, if applicable.
When Tiamat enters the battlefield, it and Cloudstone Curio trigger.
Resolve the Cloudstone Curio trigger, choosing to return nothing to your hand.
Resolve the Tiamat trigger, causing you to search your library for up to five Dragons and putting them into your hand.
Cast any Dragon from your hand without paying its mana cost.
When the Dragon enters the battlefield, Cloudstone Curio triggers, returning Tiamat from the battlefield to your hand.
Repeat.

Tiamat

Cast Moritte by paying {0} due to Dracogenesis. Choose to have it enter as a copy of Marang River Regent that is still legendary.
When Moritte enters, it triggers, returning Marang River Regent from the battlefield to your hand.
Cast Marang River Regent by paying {0} due to Dracogenesis.
When Marang River Regent enters, it triggers, returning Moritte from the battlefield to your hand.
Repeat.

Return any number of nonland permanents from the battlefield to their owner's hand

Moritte of the Frost

Cast Ebondeath from your graveyard by paying {0}.
Activate Phyrexian Altar by sacrificing Ebondeath.
Repeat.

Infinite colored mana

Infinite creature sacrifice triggers

Infinite death triggers

Ebondeath, Dracolich

Phyrexian Altar

Cast Ebondeath from your graveyard by paying {0}.
When Ebondeath enters, The Sibsig Ceremony triggers, destroying Ebondeath and creating a 2/2 Zombie Druid creature token.
Repeat.

Combos with "Dracogenesis"