Malcolm, Keen-Eyed Navigator + Magmaw + Amoeboid Changeling + Adrix and Nev, Twincasters

Malcolm, Keen-Eyed Navigator

Magmaw

Amoeboid Changeling

Adrix and Nev, Twincasters

How it works

1. Activate Amoeboid Changeling by tapping it, causing Magmaw to gain all creature types until end of turn.
2. Activate Magmaw by paying 1 and sacrificing another nonland permanent, dealing 1 damage to an opponent.
3. Malcolm triggers, creating two Treasure tokens.
4. Activate a Treasure by tapping and sacrificing it, adding 1.
5. Repeat from step 2.

This clever loop turns Magmaw into an honorary Pirate with the help of Amoeboid Changeling's continuous changeling and activated type-granting abilities, allowing it to trigger Malcolm, Keen-Eyed Navigator whenever it deals damage. Once Magmaw sacrifices a nonland permanent to ping an opponent, Malcolm's triggered ability steps in, and Adrix and Nev, Twincasters doubles the resulting Treasure tokens to generate a surplus of mana and fuel infinite sacrifices.