Kubera Leez: Best case is she find some sort of peace after her struggles and finds some sort of meaning in all that she's fought for beyond responsibility. Rather than dying, maybe living at least a few years in peace among her loved ones (like Kaz, Haas, Yuta, Mirha, and Ran) and helping the world adjust to being completely cut off from magic, acting as the last "God". Worse case she dies miserable after accomplishing nothing because it was a battle attrition and she just couldn't keep going any more.
Yuta: Best case he controls his hunger enough to actually be able to support Leez throughout her life and as he follows her path, he learns how to be a proper king. So even after he's no longer able to be in the human realm, he can lead his clan well until the end of the universe. Worst case he succumbs to his hunger and ends up killing Leez and just cares about nothing and just runs wild with the rest of Chaos clans killing all the Sura and Gods.
Asha: I think she'll die before the series is over, maybe even at Rindhallow. So for her, I hope she gets a proper conversation with Leez and apologizes so that Leez can have some sort of resolution with her. Hope she resolved things with Brilith too and they both get to tell each other exactly what it is that they've been hiding from each other. Maybe in doing so, she'll finally feel as close to Brilith as Brilith feels to her. Worse case, she says nothing to everybody and dies only knowing that part of her plan has been set in motion with characters only finding out later the full implications of what she has been doing and everything falls into chaos.
Brilith: I think she'll also die before the series is over, but like Leez, I hope she finds more to her life than responsibility. Like, let her find value in herself and take pride in what she has accomplished instead of the current "man I died how dare I not do more" mindset. And you know, work things out with both Agni and Asha. I feel like Asha would die before her, I hope at least Agni will stay with her until the end she dies. Worst she dies before she takes charge of her own life and while she still has her super self deprecating mindset. I don't think she'll live so it's really how she dies that makes it good or bad.
Agni: Best case, he works things out with Brilith before he leaves for the Gods' realm (maybe even get with her if he's lucky). I hope he fights for neither the Sura nor the Gods during whatever war there will be, because that'd be interesting and his current stance isn't particular on either side. Then afterwards if he's still alive as a God I guess I hope he's happy doing his thing in there. Worst is Brilith dies because of his bad decisions and he goes ballistic and his character reverts to being cold and uncaring (probably not for eternity but I can imagine him not taking failure so well if his reaction to the mysterious woman dying and being taunted that he couldn't do anything about it is any indication). And it'd be especially shitty if in the middle of all this he get himself obliterated from existence.
God Kubera: So many people need find peace with themselves. This guy too. Best case he stops doing what he feels like he's obligated to do, and teams up with Shess and Airavata and whoever is backing him in doing what he wants to do. I still think he'll end up ending his existence so that Leez can be God Kubera instead, but hopefully only after he's quit his suicide path. Worst case, he goes through with his current plan and dies.
Ran: Convinces Rana not to never age and get married to her where they're happy because wow that's a pretty functional relationship they got there. He becomes the priest of water, and lives a long life. Worst he dies and Leez is left with no one to care about her other than Yuta who, thanks to his appetite, doesn't care about her for reasons as pure as Ran's.
Gandharva: Teams up with Agni! Get that friendship that transcends the races! Other than that, I hope he comes to terms with his daughter's death and starts taking a path that he would be proud to take, instead of wiffling about helping Sagara. Worst case, Agni is finally forced to kill him. Come on their alliance has been dangled for so long.
Maruna: I think...he's going to die too...but the worst way for him to die would be if Yuta killed him in a fit rage after finding out that the Garuda are planning to have him killed. At least have a good parting with his siblings.
Sagara: Best she gains the respect of the other Anantas, whether or not she keeps the position of king (although I think she'd prefer to keep the position). She reconciles with them and cares about them the way a king should, and she doesn't have that complex where she's bitter about other leader figures actually being liked because she's more secure. Worst she dies accomplishing nothing but causing the ruin of her clan.