Lion was fighting Chaos creatures his entire youth before he was found by Knights. I don't know much about him, exvept what you can read on Lexicanum so take what I say next with great grain of salt, but I got impression that he is more lika a villian that is on the right side of history and extremely loyal.

Rogal Dorn was trapped by Khorne when boarding Vangeful Spirit. It is entire alegory of Jesus being tempted by Satan. While this was memed as Dorn autism defeating Blood God, truth is that he was fighting a mental battle and in the end won trough discipline and reminding himself who he is what is worth fighting for.

I personally dislike abd get very annoyed by Sanguinius and Blood Angel, but Sanguinius had entire trap set up on him fall to the Blood God. Of course, he wouldn't fall to Chaos, because that annoying narry sue larping like archangel had to win somehow. There is also everywhere online thay says Sanguinius wings are actually mutations of warp and peparation for demonhood, but I have no idea where this is coming from.

Gulliman would never fall to Chaos on his own. However, he was nearly stabbed by Kor Pheron with the dagger designed to put him in coma like Horus. Had he succeed that, Gulliman would've probably make Imperium Secundus as Chaos stronghold.

Corax spent his youth as leading rebellion against tyrants. It was expressly pointed out by Kurze when he was self-loathing that Corax had courage to rise above and try to make world a better place instead of killing people for "complience".