I interpreted this: //"Burning. Overwhelming. Power. It as the scream of a thousand warriors on the battlefield. It was the moment of most sensual touch and ecstasy. It was the sorrow of loss, the joy of victory. And it was hatred. Deep, pulsing hatred with a pressure to turn all things molten. It was the heat of a thousand suns, it was the lives of all men wrapped up in one, defined by everything they felt."//
As indicating "the burden of God's divine hatred"--in that it is everything that God "hates" and the anger shown in the hatred of it, so not just the emotion of hatred, but the embodiment of what God himself would proclaim to hate: selfishness, power, angry, murder, lust, emotion devoid of focus. All of this filtered through what Rayse himself hated--which is probably the idea of God himself and all who now embody portions of him/Adolnasium. It even seems like he's willing to give himself to others as the focus/object of their hate: "blame me--I did this" in order to channel that emotion into Odium's own power--a self-fulfilling cycle of hatred. Sustaining hatred at that level is too much.
Which also, to me, would explain why Odium might have splintered off the more uncontrollable parts of god's hatred: gluttony/lust, passion for the kill, etc. They interfered with his ability to strategize. But I don't know about that. Those splinters now have their own separate intentions, which Odium obviously has no idea might act differently when divorced from his divine hatred.