The premise I'm building on is they are the remnants of the Flame Falcons chapter who escaped the purge by the Grey Knights, since it was never established that they actually got the whole chapter. I'm planning on calling them The Immolated.
The only thing I've decided on for sure is that every unit that can have the Icon of Flame will be getting it.
I'm also planning on kitbashing the models with Loyalist Marine parts and every bit of flame motif I can get my hands on. This is to represent their mutation of bursting into flames in combat. And also because they are really just renegades who haven't fully embraced Chaos (though they are being slowly corrupted without their knowledge).
All that said, what units should I look into that fit my theme? I'm trying to avoid the more heavily mutated ones, though I might get some flame elemental models to represent spawn or possessed.
Edit: I'm avoiding Cultists unless I can think of a really good reason to include them. These guys only turned out of being furious at the Imperium for purging a loyal chapter, not because there was anything inherent about Chaos that appealed to them. As a result, they would probably not welcome Cultists into their ranks.
Edited by Claws and Effect, 13 February 2018 - 11:15 AM.