Cast Trickery Charm by paying {U}, giving Reckless Fireweaver the Pirate creature type until end of turn.
Cause an artifact to enter the battlefield under your control.
Reckless Fireweaver triggers, dealing 1 damage to each opponent.
Malcolm triggers, as Reckless Fireweaver is a Pirate due to Trickery Charm, creating a Treasure token for each opponent dealt damage this way.
When the Treasure(s) enter, Reckless Fireweaver triggers that many times.
Resolve the first Reckless Fireweaver trigger, dealing 1 damage to each opponent.
Repeat from step 4.

Infinite colored mana

Infinite damage

Infinite Treasure tokens

Malcolm, Keen-Eyed Navigator

Trickery Charm

Reckless Fireweaver

Cause Protean Hulk to die.
Protean Hulk triggers, searching your library for Lesser Masticore, Reckles Fireweaver, and Arcbound Ravager, and then putting them onto the battlefield.
Activate Arcbound Ravager by sacrificing Lesser Masticore.
Lesser Masticore triggers, returning itself to the battlefield.
Reckless Fireweaver triggers, dealing 1 damage to each opponent.
Resolve the Arcbound Ravager ability, putting a +1/+1 counter on it.
Repeat from step 3.

Infinite death triggers

Infinite ETB

Infinite LTB

Infinite sacrifice triggers

Grumgully, the Generous

Protean Hulk

Lesser Masticore

Arcbound Ravager

Activate Duchess by paying {1} and removing a quest counter from a permanent you control, creating a Junk token.
When the Junk enters, Reckless Fireweaver triggers, dealing 1 damage to each opponent.
Quest for Pure Flame triggers, putting a quest counter on it.
Activate the Junk by tapping and sacrificing it.
Rose triggers, adding {R}.
Resolve the Junk's ability, exiling the top card of your library with the ability to play it until end of turn.
Repeat.

Exile your library with the ability to play the exiled cards until end of turn

Duchess, Wayward Tavernkeep

Rose, Cutthroat Raider

Quest for Pure Flame

Activate Duchess by paying {1} and removing a quest counter from a permanent you control, creating a Junk token.
When the Junk enters, Reckless Fireweaver triggers, dealing 1 damage to each opponent.
Quest for Pure Flame triggers, putting a quest counter on it.
Activate the Junk by tapping and sacrificing it.
Crime Novelist triggers, adding {R} and putting a +1/+1 counter on it.
Resolve the Junk's ability, exiling the top card of your library with the ability to play it until end of turn.
Repeat.

Infinite +1/+1 counters on a creature

Crime Novelist

Activate Feldon of the Third Path by paying {2}{R} and tapping it, creating a token copy of Diamond Lion with haste.
Reckless Fireweaver triggers, dealing 1 damage to each of your opponent.
Activate Diamond Lion by tapping it, discarding your hand, and sacrificing it, adding {R}{R}{R}.
Thornbite Staff triggers, untapping Feldon of the Third Path.
Repeat.

Feldon of the Third Path

Diamond Lion

Thornbite Staff

Combos with "Reckless Fireweaver"