Arceus is immune to all walls. The simple solution is to level up the one the current wall is weak to and hit it with fast wave. This works wonders with scizor prime, umbreaon UD, mewtwo, shedinja, MrMime. Psy arc + fast wave = bye bye mewtwo
Phione: I agree with you about Arceus being a very difficult deck to play.
However, I don't agree with DGX. I think the SP decks (luxchomp and Dialgachomp) have been played for so long and so over analyzed that they are almost autoplay.
The thing with DGX is it is very easy to make a mistake and the best players usually don't make those mistakes. Of course I am not one of them lol.
You can hand anyone who is very familiar with the game a DGX deck and they can probably play it somewhat competitively. With Arceus I think you really have to play it well to compete at all.
Arceus isn't that difficult to play imo. I just think of it as a sort of matching thing. Just think of which attacks to use with what Arceus against what your opponent is doing, then try to see how to set that up. Of course the setting it up part is easier said then done but you get used to it quickly.
I think the ONLY real counter to Arceus is too have a Flygon Deck, just saying it would be interesting because once you discard all thier stadiums with Sand Wall they are screwed.