There are most definitely ways to counter many of the 'mons being suggested for the suspect list. I think it would do us all an amount of good to make your suggestion without attaching any emotional investment or opinion to it. It's the "suspect list", not the "Get this thing the bloody hell out of OU" or "please bring this thing back" list.
That being said, I actually -will- suggest a Pokemon to be tested that I myself absolutely loathe dealing with. Sableye.
Let's start with what I do know about the pokemon. Sableye has a very great defensive typing (Dark, Ghost), which provides it three immunities (Normal, Psychic, Fighting). It resists Poison moves, and it's lone weakness is the newly arrived Fairy typing.
Fairy types are a -very- potent type to deal with in the current tier. Clefable and Azumarill are very threatening pokemon. Un-Mega-Sableye however, can use the move 'Will-o-wisp' and "always" outspeed due to it's default go-to ability (Prankster), which burns the target and cripples it's Attack stat. That effectively nullifies most Azumarill as a check, because the move of choice to dispose of Sableye would be 'Play Rough', a physical move that will be hindered by the burn.
As such, Clefable is the lone outright check for this pokemon, outside of burning or poisoning it to whittle it down over time. Sableye on a cleric team without a mega stone is problematic enough. Mega evolving it grants it access to 'Magic Bounce', which is an equally problematic ability in that hazards and effects will not afflict the target, and in many cases, will the user instead. You have to be -very- quick on the draw to poison or burn this pokemon, because if you don't, you can get absolutely shut down by a strategically timed Mega Evolution.
This pokemon also gets access to the recovery move 'Recover', which makes getting rid of it, even harder. With all of the priority utilities, the typeing, and the mega evolution granting it a different niche it can switch to easily without needing to alter the set much from the non-mega form, the last thing this pokemon really needed was recovery, but it has it, and it can be used without the mega with priority.
To wrap it all up, Smogon provides a viable set for this pokemon to be used in an UBERS situation as it is. It seems like I'm not the only one who could make this argument.
I don't care if this thing stays in OU, and I know I'm not the most reliable person to make a suggestion for stress testing pokemon, but if there was ever a pokemon I felt was a bit lowly tiered, this one is probably it.