Immolator

You Light a Path for your Friends to survival, and you curse your enemies as the impure. You've learned that your survival is to light an Altar to the Gods and cleanse the Evil.
Sacrificing your Health isn't the worst, really. In fact, it's what you need. But a single hit will take you down, and it's over. You can prevent this however, by keeping your heat at 400% and maintaining it until an Enemy attempts to take you down. You can deal pretty massive amounts of damage, not to mention you can boost your Allies.

[Lore]
The Flamer Unit identified as 'CHAOS' was designed to create heat from the air, utilizing thermite energy as the main source. The Unit is what keeps Immolators immune to flames. If the Unit is overheated or too damaged, it'll detonate as it cannot handle that amount of thermite.
[Fanmade]
Ever since the UMG's CEO has been swapped out, people were pretty pissed at how a man of bigger greed was given power. Immolators however, were burning with complete passion with the will to create something stronger to prove the Agency is much more refined than Ulacylon. Not only did they install additional augmentations into the Unit 'CHAOS', but that heavily improved the ability to withstand Explosives and excessive Heat. However, the Overheating problem still lasted, just harder to get to. To navigate through this complication, Immolators insisted to install a similar system to how Lazarus Nanobots function. However, this used Heat instead to cauterize all wounds instead of just the bleeding, also cooling the Heat down.
This is one of the biggest Technological Revolutions in the Agency's History.