Mayael's Aria + Dark Depths + Thespian's Stage

Mayael's Aria

Dark Depths

Thespian's Stage

How it works

1. Activate Thespian's Stage's second ability by paying 2 and tapping it, causing it to become a copy of Dark Depths.
2. Thespian's Stage triggers, causing you to sacrifice it and create a 20/20 Marit Lage legendary creature token.
3. At the beginning of your next upkeep, Mayael's Aria triggers, causing you to put a +1/+1 counter on each creature you control, gain ten life and win the game.