>>22243124>In the end, He hath reclaimed their power so that they may return to emptinessThat also implies the destruction of everything pretty much. That's in relation to the end times. And this isn't the end times like Kyogre and Groudon. If your god wants to bring about destruction it does.
And not only that it relates to the Christian god specifically. In western cultures that may be the norm, but Christianity isn't the religion of the world.
And that statement doesn't even imply that the God gets more powerful. The Christian god is all powerful. He can do anything. He wouldn't get stronger by reclaiming that power. It even says the reason. So that they may return to emptiness. If you are all powerful you can't get more powerful.
Honestly what makes the most sense is to give Arceus a new form. Not a primal or a mega. Those have it getting power from outside sources. Which a god shouldn't need. And shouldn't benefit from. They can however have the power come from itself. And just have it be a form change. That makes sense. And it still doesn't take up a mega slot. I don't know why people instantly have to go to primal. They existed form changes before primals.