Hey there, interesting team. I personally don't really like screens, but it works alright in ladder games. If you're running dual screens Deoxys-S, I think you can use an EV spread of 252 HP / 236 Def or SpD / 16 Speed Timid. This outspeeds Deoxys-A, the next fastest Pokemon. Max speed is not really necessary imo, and I don't think there's much use in tying with other Deoxys-S since there are Magic Coat mindgames and speed tying for Taunt is not very reliable. With screens Deoxys actually has usable bulk, so it would possible be able to come in a few times. It would be nice to fit Recover by perhaps using another Stealth Rock user, but there's not much room for that.
I find Psyshock a weird option on your set since it doesn't particularly hit anything. It worked decently on Sub Xerneas IMO because that set is more anti-stall, and Xern needed a way to break Specially Defensive walls ie Blissey (pretty uncommon now). Thunder would do a bit more overall since it has high BP. If Yveltal gives you trouble you can use 24 Defense EVs (give Genesect SpA boost so it doesn't spam powered up Iron Heads) and put the rest in HP. Otherwise, your spread is more physically bulky which really helps against Extreme Speed revenge killing attempts.
Regarding EKiller, I don't really think you need a bulky set, especially with dual screens. Max Speed Jolly Life Orb just hits significantly harder, and overall I've found that status (Will-O-Wisp, EKiller's main issue) is less common due to Primal Groudon. With screens you can set up a couple SDs and proceed to plow through a team. Also Brick Break is not really necessary. Dual screen teams are much less common than you think, and Arceus really needs Earthquake to hit Primal Groudon.
Anyway, that's all I have. Ditto sort of band-aid checks a bunch of stuff so technically you can manage everything, for the ladder this is probably enough.