Sorry for the rant but this social network has many positive things... unfortunately the Arcane fandom is not among them

And no, this doesn't mean that I consider suicide an act of weakness, I specify it again because social media works like this: if you say you like apples then it means you hate pears.

"Well, Viktor is the one who gives him a reason to live."
Maybe in this universe, Vi's death is his new reason for living. He doesn't let prison overwhelm him, he takes responsibility, and decides to live, taking her with him.
It's a great act of strength, and Jayce possesses great strength

Jayce has one of the most interesting story arcs, not just in Arcane, but in general. I could spend hours analyzing it (which I won't do here I have a 200-ch limit per post and English isn't my first language) and you boil it down to "he's too depressed to go to the gym and face prison life"

I get the impression that you consider Jayce's character only in terms of his tendency towards self-pity, or that his empathy, kindness and the externalization of his emotions (rare in a male character) are the equivalent of "he can't do anything without someone to guide him oh poor child"

Examples:
-his mentor threatens to destroy the only thing that can save Viktor, so he kicks him out;
- he kills a child and realizes that Zaun cannot be oppressed any longer and confronts the Council;
- his dream is the cause of the apocalypse, and he tries everything he can to prevent it

Note: when Jayce attempts suicide, he feels he's being wronged by those around him, but in the other universe, it's HE who's committed the wrong, and that's the big difference! When it's about himself, he tends to get depressed, but when it's about others, he reacts.

Have you ever considered that perhaps, after killing an innocent woman with his dream, he felt it was just punishment to live in her memory and bear the burden of her unfulfilled dreams?

(In the rant that will follow I am not minimizing the suicide but Jayce is not only that)