[B]Synopsis:[/B]

Mixed Psychic Surge Deoxys-Attack is able to break through most defensive cores given minor chip (which if you see the billion other offensive mons, it’s easily achievable with how many checks they share). Deoxys-Attack also provides natural speed control as the second fastest (viable) mon in the meta. Psychic Terrain provides priority insurance for Speed Boost Palkia-O and Destiny Bond cheese, anti-Prankster Parting Shot for Ghostceus and Lunala, and jacks up Lunala’s boosted Stored Powers to absolutely stupid levels. Lunala can click Final Gambit on Ice Scales Arceus, or Yveltal so either the dragons or Ghostceus breaks through. Ting-Lu improofs Deoxys-Attack, has basic hazard control and provides a secondary Prankster immune if you wanna play safer. The rest improofs themselves through Plates.
As expected with HO, play aggressively. Like, [I]really [/I]aggressively. One wrong predict could lose you the game, but a correct one can swing the tide into a win. I usually lead Deoxys-Attack -> Ting-Lu Teleport but Ghostceus leads can surprise your opponent too.

[B]Weaknesses: [/B]

- Sticky Webs: Funnily enough, this entire team falls to Sticky Webs if Ting-Lu can’t remove them. Your ghosts are suddenly slower than everything and their mothers even boosted, Deoxys-Attack fails to serve as proper speed control, and Palkia-O/Eternatus can simply be Boomburst’d to death by Mega Diancie.

- The improof for Spooky Plate Imposter is really, really sus (you’d essentially have to trade your Ghostceus/Lunala [I]and [/I]one of your Pranksters to maybe get rid of it) but that set’s incredibly uncommon so it’s probably fine.

- Mega Diancie: You have no true check here. It’s either saccing wars between your Deoxys and their Diancie, or a “will you take the dbond bait or will you simply switch out” gambling simulator.

[B]Other Options:[/B]

- V-Create > Headlong Rush is an option on Deoxys-Attack to immediately 2HKO Mega Steelix, but the improofing becomes rather difficult afterwards. Collision Course is also an option here. (improof with Aegislash)

- Nasty Plot > Torch Song [I]and [/I]Armor Cannon > Sludge Wave on Eternatus trades off it’s ability to threaten Mega Diancie (without sacrificing itself) and Fairyceus (immediately) for much more immediate firepower. You can also scrap the set entirely and settle for a NP + 3A Moldy set instead, but I’ve found 1 Prankbonder to not be enough most of the time.

- Desolate Land Reshiram could work over Palkia-O, but it makes the team a bit slower in the speed department (and also I haven’t tested it)