Volcano Hellion + Metropolis Reformer + Angel's Grace

Volcano Hellion

Metropolis Reformer

Angel's Grace

How it works

1. Cast Angel's Grace by paying , causing all damage that would reduce your life total to less than one this turn to reduce your life total to one instead.
2. Cast Volcano Hellion by paying 2.
3. When Volcano Hellion enters the battlefield, it triggers, dealing an arbitrarily large amount of damage to you and Metropolis Reformer, with your life total instead becoming one due to Angel's Grace.
4. Metropolis Reformer triggers, causing you to gain life equal to the damage dealt to it.

This clever lifegain loop relies on setting up a bizarre safety net with Angel's Grace, ensuring that the colossal damage you're about to deal won't actually eliminate you. When you deploy Volcano Hellion, its enters-the-battlefield trigger allows you to target yourself and name an arbitrarily large number of damage, which Angel's Grace limits to just dropping your life total to a safe 1. Meanwhile, Metropolis Reformer absorbs that exact same massive chunk of damage and its static lifelink-like ability triggers in response, flooding you with a colossal amount of life because of the sheer scale of the blast.