[@CleanBreeze] I like that idea quite a lot actually. though one quibble i see is that exile seems unlikely if the legion and primarch were purged entirely from history, as the unknown legions are in current lore. That said, some kind of self imposed exile after fleeing from destruction would be entirely sensible IMO. a small point as well, the purged legions i think happened well before the Heresy. That said i could be wrong, im not an expert. more info in the unknown legions if you are curious: https://wh40k.lexicanum.com/wiki/Two_unknown_legions