Saheeli Rai + Sun Titan + Mirrormade + Encroaching Mycosynth

Saheeli Rai

Sun Titan

Mirrormade

Encroaching Mycosynth

How it works

1. Activate Saheeli Rai's second ability by removing two loyalty counters from it, creating a token copy of Sun Titan with haste.
2. When the Sun Titan token enters the battlefield, return Mirrormade from your graveyard to the battlefield as a copy of Saheeli Rai.
3. Put the oldest Saheeli Rai in your graveyard due to the legend rule.
4. Activate Mirrormade's second ability by removing two loyalty counters from it, creating a token copy of Sun Titan with haste.
5. When the Sun Titan token enters the battlefield, return Saheeli Rai from your graveyard to the battlefield.
6. Put the oldest Saheeli Rai in your graveyard due to the legend rule.
7. Repeat.