Alright so I used Sableye and it turned out quite nicely despite losing 3 in a row near the end.
Here is the screenshot:
And here is a reply of one of the better battles:
The Sableye set i used is this:
Sableye (F) @ Leftovers
EVs: 252 HP / 252 Def / 4 Spd
Impish Nature (+Def, -SAtk)
- Foul Play
He's incredibly underrated in its ability to spinblock Forretress and Excadrill effectively as well as its main selling point - priority Will-O-Wisp. Here's a common scenario - you have say, Tyranitar in on an Excadrill and they obviously want to spin. Arceus Ghost could switch in here, but risks the Swords dance on the switch and a +2 EQ killing or nearly killing it. Sableye, however perfectly counters Excadrill no matter what it does (given WoW hits).
Will-O-Wisp allows Sableye to cripple all physical attackers in Ubers except Ho-Oh and Blaziken while 2hkoing the former with Foul play. It is an incredible check to Arceus with Foul Play doing upwards of 70 percent after a +2, and OHKOs after +4. Reliable recovery in the form of +1 priority Recover goes along perfectly with Will-O-Wisp. If a Rayquaza is locked into Outrage, Sableye can Will-O-Wisp it the first turn and spam Recover and Foul play it to death later.
While some may argue Sableye is still outclassed by the other bulky Uber ghosts, Sableye possesses priority Taunt to cripple so many threats in Ubers. It taunts the Sleep talk of Giratina/Kyogre, Taunts the Calm mind/Recover of Arceus formes - the defensive set beats Arceus Fight 1v1 - and even plays effective mindgames with Groudon leads. I try to lead off with Sableye against Sun teams and Taunt the Groudon first turn. If they switch Ho-Oh in on the taunt, I can simply go to T-tar and set up Rocks to get an early advantage. If they EQ, it only does around 49 percent from standard Groudon, missing out on the 2hko.
As for supporters, I found that Ferrothorn and Tyranitar are great teammates for Sableye. Max/max special defense Ferrothorn takes most of the special hits aimed at Sableye, especially from Kyogre who often switches in. Tyranitar is for Fire-blasting Palkia/Dialga as well as Ho-Oh. These two supporters can play mindgames with the opponent with their unique resistances and immunities while the Sandstorm/Hazards slowly chips away at the opponent.
So all in all, Sableye finds its niche in the Uber metagame with its Prankster ability which allows it to stop or cripple numerous threats as well as serving as an effective Spinblocker.
Huge credit to my man Donkey for building most of the team.