>>18112981The biggest hurdle in battlespot is dealing with the item clause.
Gliscor is stupid popular on battlespot for a reason, very few other Pokemon compete with it for Toxic Orb usage. This lets you use Leftovers and Black Sludge on other things.
Chansey is also great because it's a Pokemon that uses Eviolite, freeing up leftovers for a bulky set up sweeper.
Mega Stones circumvent item clause naturally. Due to the nature of 3 on 3 you can actually have two Megas in your starting 6 and then pick whichever one will work best depending on the situation.
Gengar is probably one of the best users of Black Sludge, SubDisable is a very good set and can single handedly demolish teams that aren't ready for it in 3 on 3.