Of the three, Sableye is one that I've really been looking at, though it's a huge investment to make one for the great league (needs to be lvl 40. The higher the IVs, the better). It's only weak to Fairy, and since there's no Fairy-type quick moves, it really only has to fear charge attacks. Shadow Claw got a nice EPS buff, so alongside Shadow Sneak and Power Gem, this could be a fun Mon to use. Just costly.
Mawile has very unique typing, but suffers from a pretty mediocre movepool. As much as I'd like to think it'll be good, I doubt it will. In some cases, it's likely going to faint before getting a charge move off.
Togetic, like all Fairy-type Mons doesn't get a Fairy quick move and it's other options (ES and HP) are just ok. HP can give you an element of surprise though, and it's charge moves are alright (though DG costs way too much energy for how much damage it does). I'd say Togetic is a middle-of-the-pack choice.
