I've been thinking about JiuHuo rescently, specifically about the infamous Qin Jiu line:
"I'm not here to save you, I'm here to love you."
I just think it's such a beautiful way to sum up their relationship and what they mean to each other.
You Huo didn't need saving, he had it all figured out. He wasn't buying the System's bullshit, he and Chu Yue were already planning a way out and how to take it down. Even if Qin Jiu didn't appear, You Huo would have tried many times to escape and destroy the System. That's not what Qin Jiu was for.
Qin Jiu also wasn't someone who is supposed to save You Huo from loneliness or his bad childhood. You Huo had friends, he was never truly alone. The bond that he and Chu Yue share is so deep and so special to him (him and Qin Jiu literally ran to her room after waking up and seeing each other when everything was over, because they were so worried for her). And he has put his childhood behind. Of course there are memories that still hurt him and affect him but he knew when to seperate the past and move on. He doesn't let that hurt affect him much in his day to day life (besides his eyes).
No Qin Jiu's role is neither of those. He's there to simply love You Huo. To love him in an unconditional way, in an unexpected way, in a meaningless way. There was no reason for Qin Jiu to fall for him or vice versa, it simply happened. They didn't need to have a big understanding of each other or some life changing event for that love to blossom, their souls just simply found each other and they never let go. They were each other's missing piece. You Huo just needed his love and to give that love back in return. And that's exactly what Qin Jiu offers.
He supports him, he joins him in his madness, shares his madness, all of that simply because he loves him.