Former Terminus scientist. Chose to study the Aether and make an Aether Resistance Vaccine to bolster Terminus troops. Jansen defects, pushing their research into overdrive to get it done. Deadbolt slowly starts dismantling Terminus. They get less and less rest as they work as fast as they can. Delirious and exhausted they present a prototype to be told it cannot be supported or tested as it would be a waste of manpower that is dwindling.
Scorned, sleep deprived - they take to the field and test it on themselves. All that work cannot be for nothing. They take it and walk straight into the heart of the Aether Storm in the EZ.
They catch the Stormcallers attention, and the Disciple is quick to approach and attach to them, attempting to drain them of their life force. It backfires. Horribly. Both are sent flying, and they are left in extreme pain as their body essentially burns. It's a transformation that is hindered by the Aether Resistance. It leaves them hanging by a thread - body charred beyond belief, new power running through their veins, molten cracks in their skin thrumming with burning light.
They wait out the storm before crawling back out into the EZ. Their mind is intact - though riddled with whispers from the Aether constantly trying to take control. They're forced to stay anchored to their body - and the existence is actually pretty fucking miserable.
They have the abilities of the Disciple but they cannot control them for shit. Sometimes they have control and it's great when it works. But it can go haywire quickly. Either leaving them lacking in any power to control the zombies around them leading to an attack on them or caving into the feral animalistic nature that drives the horde, becoming no better than another Disciple for a short period of time before pain brings them back down from it.
There is no saving them. They know that. They're stuck in this existence now. They dress similar to other Disciples, though they always walk. They cannot float like the others - a reminder they're still somewhat human. They keep a hood/mask on at all times. No one wants to see their face - which is charred, burnt up and cracked like the rest of their body.
Going with this for the appearance.
Just gotta name them and wrinkle out details later but there's the basis-
update; name is Vasiliy (Vasya) Antonovich Katayev. Started going by Wither post incident though still respond to their birth name. obviously.