I am a very poor writer so I get insanely nervous explaining my ideas for anything, but I have so many ideas right now and I've seen so many cool "healed Bi-han" or "post Khaos Reigns" ideas that I'm just going to share mine anyway lol
My idea is that the damage of becoming Noob is too much to ever be "healed" and that if he could ever be fully healed it would take many lifetimes. So, Liu Kang helps Bi-han manage the Khaos energy and stabilizes him but for the most part Bi-han is back at square one if he wants to be a "good guy". His Cryomancy that he was so proficient in is forever off the table as the khaos energy within him shatters and destabilizes any sort of ice construct he'd make. So, he has to master and rebuild a strong magical foundation with darkness as his primary element.
He'd be able to use Khaos magic and that would be exponentially stronger than his shadow magic but using it recklessly does corrupt him. Knowing that, he'd wander the realms looking for ways to manage and control his khaos magic and strengthen his shadow magic. Knowing he could kill titans with it, I'd like to think he'd never really choose to completely abandon khaos magic and that he'd always be a wildcard with it. I like the idea that he'd have to control the impulse to use that power recklessly. Every time he uses khaos power is a calculated risk, and everyone just needs to pray he is good at math when he uses khaos to get anything done.
Lastly, it is a bit mean of me, but I also like to keep him looking more like Noob and less like Sub-Zero because looking less human would mean that he cannot wander around Earthrealm freely anymore. So, if Earthrealm was in trouble and Liu Kang asked him to help, he'd literally have to work in the shadows- No personal glory. He'd have to help because he wanted to do the right thing and no other reason. Plus, I think wandering the other realms would be good for him. Maybe he'd better understand other characters and be less judgmental of others by the end (maybe... hopefully).
Anyways, thanks for reading my slop if you made it here. I am also okay with completely evil forever Noob. But the idea of a "trying to be good" Noob who is doing his own thing is fun to me personally









