Hey guys, first ever post but I really love the Dornian Heresy and have been waiting for it to resurface
Anyway it's been a while since I read the fluff here on the Salamanders but I have had some thoughts on how Vulkan can end up in the hands of Malal, feel free to tear this apart as you see fit as I'm really rusty on the what's established here and the norm-verse fluff.
Vulkan lands in the lava lakes as mentioned and is horrifically burned, he is turned away from the villages and chased off as a monster, (he'd only be a boy here so not a massive threat to a gang of armed blacksmiths) he scavenges from the land and watches two things of interest; first the villages as they show a bond of unity he has never seen before, and the mighty salamanders who roam at will and do as they please. This kindles in his heart a desire for acceptance into society and feel that bond of belonging, yet it also ignites a respect for the solitary salamanders who have mastered this world through sheer force of will and natural brutality.
He fights the eldar on many occasions and becomes adept at the art of battle. He is still not accepted by the villages but they no longer shun him as extremely and even let him live on the outskirts of their settlements where he can build his own forge for his wargear. This state of tolerance does not sit right deep in Vulkan's heart who knows that he will never be one of them, he will never be truly accepted. His respect for the salamanders only grows as he realises how free and independent they are, he begins to emulate their self-interested ways and shuns the villages in turn. He now longs for the eldar raids as it is the only time he feels he truly interacts in another being in a way more intimate than tolerance.
The arrival of Emperor naturally calls Vulkan to him as the display of might and individual strength is akin to the salamanders. The Emperor tells Vulkan that he has a place for him in the Imperium, Vulkan can't believe that he would be accepted and is eager to leave but is not willing to join the Emperor if he is like the villagers; Vulkan wants to follow a man with the heart of a salamander. To prove his worth the Emperor must kill a bigger salamander than Vulkan, which he does and just like the norm-verse must toss it in order to save the dangling primarch. With this Vulkan feels he can take a place worth having in the Imperium, as long as it is filled with men like this Emperor. He names his legion after the figures of his idolisation; the Salamanders, and will turn them to emulate the reptiles as much as possible through inner-strength and a fiery aptitude on the battlefield.
So I haven't really thought much about the Crusade days themselves but I was thinking that Vulkan feels his is being treated the same way as he was on Nocturne; a distant tolerance, which he cant accept and so when Dorn, one of his closest allies, tries to convert him he readily agrees to turn his back on the Emperor he once thought better of.
Skalathrax. He is where he turns from chaos and I think I have a good solution, as well as why they lose. The fighting has reached a stalemate and just like the norm-verse Khârn has had enough and takes a meltagun to go primarch hunting. During the fighting Khârn manages to loose a shot off at close quarters and burns Vulkan's face, now in Nick Kyme's trilogy Da'kir has the same treatment and has a half normal face for it, this is what happens to Vulkan. This single action has many after effects including the immediate retreat of the Salamanders in order to preserve their wounded primarch. More importantly Vulkan feels like Chaos has betrayed him; so many promises where made but they all went up in smoke when Vulkan realised he was disposable, he wasn't special and he wasn't truly wanted or accepted. This sense of betrayal drives the primarch from Chaos, in his meanderings he starts to see hallucinations in the reflections of his new black and white face; visions of Malal. Malal reveals to him the true nature of chaos, he reveals that no group can be truly cohesive as the nature of chaos always drives a wedge in somewhere; it is the natural order of things. Malal wins Vulkan over with talk of true anarchy and self-reliance. Fight the Imperium, fight Chaos, fight everyone as no-one is an ally and no-one is truly an enemy; no-one deserves such lofty titles. Only rely on yourself, the universe will always turn on you. Vulkan takes his legion and begins to wage war in the name of Malal.
Another side-effect would be that Khârn proves the loyalist Legions can fight the Traitor Primarchs even without their own counterparts. Hope is kindled in an otherwise beaten Imperium.
So there it is, my ideas are finally written down somewhere and are at the mercy of your judgement. Do with them as you will. This is your project after all. I just wanted to throw a possibility into a problem since I desperately want the second half of the Dornian Heresy Legio Imprint