
I totally agree whit you I'm on RiverxHeil boat, and I think that the reason of why Kaveri and Khaol can't have their own happiness is because Khaol is reluctant to let his immortality and power, so for me they would have their happy "ending" if they go through the river of the underworld and reincarnate and try to find themselves again. But for that to happen he has to give up on those things.
Because let's be realistic here, Kaveri won't be happy in the way he is right now, we all have to agree that Khaol is the worst partner, is not just because he let River die (and that a very BIG deal here and the upmost betrayal) but he is also making his "true love" suffer because of his egoism and self pity.
If Heil and River don't end up together, I'm gonna flip the underworld and dry all the rivers in the world! That is, if I can. ╮( ̄▽ ̄)╭
No matter what the back story of Khaol will be or any reverse emotional ride for what happened, he and Kaveri belong to each other. Their love had endured more than a thousand years. Just give those two a happy ending. Please. Heil + River, Khaol + Kaveri. Let's not make this amazing story so damn frustrating in the end. Although Khaol was a jerk, he still deserves to be happy, and Kaveri, too.
That so understanding and loving Heil? That sacrificial and kind River? Those two. They belong together.