I re watched the anime and I guess the first time i wasn't really paying attention (I've also re-read the manga I think i might just be illiterate) but I think Ruby's wish for Aqua to find the murderer is what ultimately re lead him down a path to once again find his revenge. I'm not gonna blame Ruby for the wish though as she was under the impression he was still looking and fighting for it. The Crow God though she knew Aqua was satisfied and still did what she did. Ill admit she's got me a little peeved.
The Crow God was orchestrating everything, was also listening to their wishes and ultimately that's what roped him in. I don't like little miss God because she seems omnipotent, but then also acts like she cares about the twins, and upon rereading up to chapter 163 and re absorbing the anime it's clear she cared about Ruby way more then Aqua as he was nothing more then a tool to make Ruby succeed in life without a hitch. She also high key admitted to Aqua's only purpose in reincarnation to begin with, was to make Ruby succeed.
Crow bitch gets bent out of shape, acting like shes soooo sad, that Aqua was breaking and that him getting revenge was going to ruin him. But she seemed to also actively be leading him down that path and even actively talked to Ruby (right after girly found the Doc's corpse) to really rub in that someone else was involved in Ai and Gorou dying. Aqua gave up on revenge because he found a good enough answer. But good enough wasn't good enough for Crow bitch because she lead Ruby to the corpse. Igniting one of the twin's need for revenge ie. Ruby's need who did not know and probably would've never assumed that Gorou was dead till then. She would've just lived her life upset that he hadn't come to find her.
After thinking about it too, the only outcome of Aqua not finding who actually killed Ai would be that eventually their dickwad father would have tried to kill Ruby. Aqua probably wouldn't have died in that time line; by then also I think he would have cared enough about Akane and healed enough to not fall apart afterward either. Even then! This is all assuming Ruby would have surpassed Ai and I don't think she would have. I think she would be decently famous and enjoy being an Idol. But eventually i think she would have had her fun and moved on. I also think regardless of the timeline she would have figured out who Aqua is. But either ending was unacceptable to Crow bitch.
I really don't like that Crow bitch acted like she cared about Aqua. The man's only needed and wished for freedom because the world he lived in, experiences he went through and memories he had were like a disease to his lively hood. Something that the shit crow actively facilitated. Ruby may not be my favorite character but I could logically argue for her actions and thoughts. The Crow God though I literally cannot with her.
She basically went "I'm so sad boohoo, you're Aqua Hoshino and you did your best. There there." The he was gonzo and acted like she wasn't the reason he was going to die.