It depends more on your team, If your team is quite physically bulky then go for Toxic, however I'd reccomend WIll-o-Wisp, because its better for longevity and shuts down opponents so the rest of your team can have an easier time.
Here's a set:
Sableye-Mega @ Sablenite
Ability: Magic Bounce
EVs: 252 HP / 4 Def / 252 SpD
Calm Nature
- Recover
- Protect
- Sucker Punch
- Will-O-Wisp
This set is completely specially bulky, with W-O-W to shut down physical attackers.
Another option is getting rid of Protect and putting on Toxic. Protect helps stall, but you honestly already have recover for stalling.
PS: I'd go Shadow Sneak instead of Sucker Punch. Often opponents will try to status your Sableye making Sucker Punch useless. the damage Sableye often puts out isn't very much, so things like Shadow Sneak ect. is usually used to finish opponents off, so the damage output shouldn't matter so much on something that isn't invested in attack.
