After a discussion with Graphyte1334 (https://www.deviantart.com/graphyte1334) , I've agreed to flesh out Orbogeddon's motives further than initially:
The Multiverse relies on the lifeforce of all of the Multiverse gods, Orbogeddon included. The problem is that, since the Multiverse is constantly using the energy of the gods, it's slowly draining their lifeforce, and if it exists for any longer, all of the Multiverse gods will die and the entire Multiverse will collapse. Orbogeddon suggests that the Multiverse be destroyed completely so that they can regain their lifeforce back, but the other gods are not willing to sacrifice their creations. A great battle took place, until Orb