Moxite Refinery + Magistrate's Scepter + Mossborn Hydra + Simic Growth Chamber

Moxite Refinery

Magistrate's Scepter

Mossborn Hydra

Simic Growth Chamber

How it works

1. Play Simic Growth Chamber. When it enters, it and Mossborn Hydra trigger.
2. Resolve the Simic Growth Chamber trigger, returning it from the battlefield to your hand.
3. Resolve the Mossborn Hydra trigger, doubling the number of +1/+1 counters on it.
4. Activate Moxite Refinery by paying 2, tapping it and removing three +1/+1 counters from Mossborn Hydra, putting three charge counters on Magistrate's Scepter.
5. Activate Magistrate's Scepter's second ability by tapping it and removing three charge counters from it, causing you to take an extra turn after this one.
6. Repeat each turn.

This clever engine leverages the bouncing mechanics of Simic Growth Chamber to continually trigger Mossborn Hydra, turning every land drop into a massive exponential explosion of +1/+1 counters. Moxite Refinery acts as the crucial conversion bridge, stripping those abundant counters off the Hydra to stock up Magistrate's Scepter with charge counters. Once the scepter is fully loaded, you can cash them in for infinite extra turns, locking your opponents out of the game completely.