Okay since this thread is basically people being obnoxious let me say a few words:
Why was Mega Slowbro banned in Monotype? Because of it's godly defense stat and the ability to not get tricked by it but it's prone to being Toxic-ed and the Rest set is ass because many types have mons to deal with that. Now let's go on to Sableye.
It cannot be toxic-ed and you legit have to rely on 6.5% to damage it. Unless you give complete offensive pressure on it, it can setup against every types except for like HO and weakness stuff like Fire and Fairy.
"
omg u let mega sableye setup u deserve to lose"
Is that how the metagame turned up to be now? In that case Mega Altaria or Zard X isn't broken as well. And Prankster Will-o-Wisp doesn't make this any easier. Mega Sableye is a pain to deal with, and in most cases gives your type a better matchup against the opposing types (given you're good obviously).
Therefore Mega Sableye is
broken and should be suspected
at least and the Metagame is worsening by not doing anything to it.
Shoutouts to
Septicus for showing me this aids