Cast Trickery Charm by paying , causing Magmaw to become a Pirate until end of turn.
Activate Magmaw by paying 1 and sacrificing another nonland permanent, dealing 1 damage to an opponent.
Malcolm triggers, creating two Treasure tokens.
Activate a Treasure by tapping and sacrificing it, adding 1.
Repeat from step 2.
This clever loop relies on turning Magmaw into a Pirate using Trickery Charm so that its activated damage-dealing ability triggers Malcolm, Keen-Eyed Navigator to generate Treasure tokens. Because Exalted Sunborn doubles any tokens created under your control, every single sacrifice yields an extra Treasure, creating a surplus of mana. You can then feed those duplicated Treasures back into Magmaw alongside other nonland permanents to machine-gun down your opponents with infinite damage.