As you may know Arceus is the god pokemon, so if we stop thinking about stats too much Kyogre and Groudon wouldn't have the slightest chance. Arceus basically is the strongest pokemon...Kyorge could take Arceus and rayquaza without groudon. 1 Ice beam from Kyogre and rayquaza's dead. Arceus Does not exell in a single stat and cannot kill either in 1 hit. If kyorge uses sheer cold and groudon uses fissure, one of them is going to hit. Everyone thinks arcues is the best pokemon ever; its not. Just because it has the highest combined base stats doesn't mean its the best. It needs to exell in at least 1 stat.
He said. He`s smart [Or not? =P]Abit unfair, Rayquaza is stronger then Kyorge and Groudon, and aruseus is stronger then all 3, so the 2 strongest against the 2 weakest?
Anyway I pick Rayquaza and Aruseus.