Yeah but can he overcome Graham's nothingness and Anos' resistance? Interaction is not the only thing you need as overcoming the resistance they have is needed too... The Anos vs Homura thread makes it very clear, and yeah Arceus still have 4-D powers. Practically the outcome is the same as
this thread, even if Arceus can interact now, if he is not able to overcome Graham's nothingness resistance and then Anos' source then it is useless. And let it be clear that no matter how fast the passives were (what happened Anos vs Eques) MEoCD didn't care that Eques' passives were faster than MEoCD as it had simply destroyed the reason even before and after being affected.
Edit. Also this doesn't work as Arceus is a Smurf... Type 9 Immortality that relies on a tier 1 being...