I hate sableye, to be honest. not because it is a bad Pokemon by any means, but because it is SO ANNOYING. Really just here to give a good moveset contrary to the other answer, so here:
Sableye @ Leftovers
EVs: 252 HP/ 252 Def/ 4 SpD
- Knock Off/Night Shade/Foul Play
This set is sooooo annoying. A sableye without will-o-wisp is quite dumb, tbh. This defensive set can take special hits and recover, and burn physical attackers. There are better Pokemon of course, but it is certainly worth training.