This is simply a variant of the Wonder Room team I've done in the past, but working in the given core this time around. Whole idea is simply to abuse the swapping of stats to set pivots and push momentum from a generally defensive front.
~ Celebi The Muscle ~
Originally I ran Mew in this slot with an EBelt for an offensive presence, so I felt Celebi could easily come in and take over that role. Life Orb chosen over EBelt for that extra juice. Serving as an offensive toolbox, I decided on running Giga Drain(Stab&Recovery), Dazzling Gleam(Coverage), Earth Power(Coverage), and U-Turn(Momentum).
~ Mega Gallade The Tank ~
I love this set so much. With a natural SpDef of 115 and Def of 95, Megallade can play itself into a Wonder Room + Bulk Up combo rather nicely. Will-o-Wisp is rather gimmicky, but it is an amazing option in that 4th slot. This allows Gallade to dump EVs into HP and SpDef without having to worry on the Def side of things quite as much while also eliminating physical threats for the rest of the team.
~ Slowbro The Wonder Wall ~
Much needed physical, but also serves the purpose of main Wonder Room setter. Assuming Deoxys is down and out early, Slowbro is the only remaining source of setting the Room for the rest of the team. Set is just general. Without Colbur support anywhere else on the team, Bro had to hold on to one.
~ Deoxys-D The Wonder Lead ~
Deoxys-D comes in and executes its role as a lead rather nicely. With access to Stealth Rock and Spikes, most often than not I'm getting hazards set. With the ludicrous stats Deo has, it can sponge hits and set the field for the remainder of the team. Another lovely niche additional with Deo is access to Wonder Room. Generally going to be looking at a layer or two of hazards along with the first wave of Wonder Room each game from Deo.
~ Latios The Muscle Pt. 2 ~
Without setting up(Gallade) or relying on special beatsticks(Gothitelle), the team's only form of offensive pressure comes from Celebi. That just isn't ideal, so Latios works itself in nicely in that sense. Webs and Toxic Spikes can cripple this team rather badly, so having a Defog option in Latios only enhances its value. For the set itself, both Scarf and Life Orb can find their uses. Your only form of speed comes from a base 100 and 110, which isn't bad but you lose to opposing an opposing scarf barring Slowbro Twaves. Scarf Latios fixes this issue while still letting you get Defog off if in dire need. On the other hand, LO gives Lati that extra punch which may be the difference in certain situations. Both items are situation depending on the match-up, but for now I have Scarf > Orb.
~ Gothitelle The Trapper ~
Gothitelle comes in as an immediate replacement for AV HoopaU. While not quite as bulky specially, Gothitelle brings the bonuses of decent def and the ability to trap targets. Sticking with the theme of abusing Wonder Room, AV just felt like the best route despite lack of recovery options. For the moveslots, I decided on
Eball / Psychic / Signal Beam / Mirror Shot
General coverage with the first few slots, but the final choice of Mirror Shot is where Gothitelle shines most imo. Given her natural bulk and the additional boost from the AV, Goth can sponge up special beat sticks decently well and KO in return.
-252 SpA Mega Charizard Y Fire Blast vs. 248 HP / 60+ SpD Assault Vest Gothitelle in Sun: 168-198 (48.9 - 57.7%) -- 95.7% chance to 2HKO
-252 SpA Choice Specs Keldeo Hydro Pump vs. 248 HP / 60+ SpD Assault Vest Gothitelle: 142-168 (41.3 - 48.9%) -- guaranteed 3HKO
-252 SpA Life Orb Latios Draco Meteor vs. 248 HP / 60+ SpD Assault Vest Gothitelle: 146-173 (42.5 - 50.4%) -- 1.6% chance to 2HKO
-252 SpA Chandelure Shadow Ball vs. 248 HP / 60+ SpD Assault Vest Gothitelle: 152-180 (44.3 - 52.4%) -- 15.6% chance to 2HKO