Dante wrote:
...snip...Is it not also feasible that the Creator and the Cosmic Dragon and the Unspeakable One have also used time travel to manipulate events to work out in the way they desire?
The biggest difficulty of analyzing time travel in Arcanis (or any story, for that matter) is knowing what the "rules" of time travel are since they differ across fictional universes and aren't spelled out for us players with merely mortal characters.
Uh...sure?
You are right that we don't know what rules and restrictions exist on time travel. (Powerful) Mortal magic once sent PCs forward to a possible future. It's not clear if mortal magic in any form can alter the past.
It seems that the PoM collectively traveled backward in time to set in motion the destruction of a race that would open up Onara to humanity (and incidentally the Issori, Ssethrics & elorii too). Did it take their combined might? A special circumstance? Is something most true divinities can do? Can Belisarda time travel? Can one divinity stop/thwart another?
We don't know. But it seems obvious to me that of course it's a possibility that other very powerful entities could time travel.
Have they?
I don't know.