Request: If the following is considered part of discussion to remove, may I request only the part pertaining to that discussion be removed?
AM Edit: I do this anyways lol
I'm not arguing that it should be lower, but can someone explain to me why M-Sableye became s-rank? Is it just because it is a staple on stall teams and can also fit onto most other types of teams easily? Every time I've ever faced M-Sableye it seemed to be kind of dead weight that just ends up burning something or knocking off and then getting 2hko'd, maybe I've just been facing people that use it wrong or I use teams with strong wallbreakers idk though
The conclusion I draw (do not hesitate to correct me if I'm wrong) is because Mega Sableye's Role compression is big for Stall Teams with all the powerful wallbreakers running around, putting Teamslots at a premium to try and handle all of them while still managing the other important Jobs.
Sableye also doesn't have the typical role compression issue of being outperformed by other mons objectively at the role. The Utility set comes out on top against practically every Rock setter bar maybe Heatran, depending on if you're evaluating it as keeping Hazards off vs. neutering the mon itself. Between Spin-Blocking and walling, getting hazards up while Sableye's alive is a crapshoot. WoW spreads passive damage and deals with Physical Sweepers, and Sableye on the whole has numerous methods to annoy Pokemon, making it hard to take advantage of as most bulky mons do. There's obviously more, but these are the most immediately obvious benefits.
As far as Gengar, I say
stay in A. I will be the first to highlight Gengar's flaws given it's one of my favorite Pokemon. It's bulk is beyond pathetic, barely able to survive anything bar 4x resists or immunities from anything intending damage over Utility (Keldeo's Scald vs Alomomola's Scald). His Attack power is good, but not great without a LO, relying on chip damage or status for Hex to allow him to break mons on his other Stallbreaker sets. Finally, the rise of Sableye, more fat grounds, and competing wallbreakers make Gengar a good option, but not a primary option any more for dismantling cores due to things he can't quite get past as well as things that get past the same and more and/or have less prominent problems.
All those considered, though, I think that's what dropped him to A from A+ already. Gengar's Speed and power in tandem are still nothing to sneeze at, having what I believe to be one of the best combinations of movepool, speed, and attack simultaneously without some opportunity cost such as the Mega Slot for things like Lopunny or Manectric. But that's just one of Gengar's sets. Whenever I face Gengar, it's a gamble counterplaying it since I have to identify the set, and then be careful predicting around it once I do. Gengar's movepool offers phenomenal coverage alongside STAB Shadow Ball, as well as plenty of utility options he or a teammate can exploit. He can break Cores through WoW + Hex, Taunt, SubSplit, SubDisable, or just through sheer power in some cases.
Gengar's typing + Ability also does it favors both offensively and defensively. Besides its STAB combination, it has immunity to two priority types in Extremespeed and Mach Punch, as well as a resistance to Fairy, bug (Utility U-Turns), a Ground Immunity (no Spikes), and Toxic. The sum of these I find in practice makes Gengar harder to wear down by means besides its own LO and stray burns, since the balance/defensive teams it does well against rely on hazard stacking for a good deal of damage. It does leave him vulnerable to Sucker Punch and Pursuit, but the former is mitigated by his Utility options (WoW in particular) and the latter by the trouble most trappers have switching into him and being able to risk the play the next turn.
All in all, I don't think Gengar has gotten less effective, just that other mons have greater incentive to compete with him than before for his role. I feel the drop to A encompassed that, but a drop to A- would entail Gengar in his own right has gotten noticeably worse at his role.