Medomai the Ageless + Alesha, Who Smiles at Death + Auton Soldier + Umbral Collar Zealot

Medomai the Ageless

Alesha, Who Smiles at Death

Auton Soldier

Umbral Collar Zealot

How it works

1. Declare Alesha as an attacker.
2. Alesha triggers, causing you to pay U/BU/B to return Auton Soldier from your graveyard to the battlefield tapped and attacking as a nonlegendary copy of Medomai the Ageless.
3. Deal combat damage using Auton Soldier.
4. Auton Soldier triggers, causing you to take an extra turn after this one.
5. Activate Umbral Collar Zealot by sacrificing Auton Soldier
6. Repeat each turn.

This ingenious loop puts the legendary restriction on Medomai the Ageless completely out of the equation by using Alesha, Who Smiles at Death to pull a fresh copy straight from the graveyard each round. When Alesha swings, she resurrects Auton Soldier, which enters the battlefield as a nonlegendary copy of Medomai, neatly bypassing the rule that prevents the original from attacking during extra turns. After that clone connects for combat damage to secure your extra turn, Umbral Collar Zealot steps in to clean things up, sacrificing the Auton Soldier so it can safely end up back in your graveyard, ready for Alesha to revive it all over again on the next loop.