Magnezone

Magnezone doesn't seem like a likely candidate for a team slot at first until you look at its amazing ability to trap Steel-types like Scizor, Skarmory, and Ferrothorn, which is useful because they can threaten a lot of the metagame's most dangerous sweepers like Mega Diancie and Tail Glow Syclant, meaning Magnezone can form dangerous offensive cores. This is further complemented by Magnezone's high Special Attack and two great STAB moves that give it good neutral coverage. Defensively, Electric / Steel typing also is wonderful for a pivot due to the many resistances it possesses, which let it get many safe switches against Fairy-types such as Clefable and Steel-types like Skarmory and Naviathan. Unfortunately, Magnezone is outshined by most Electric-types, which have more speed, coverage, and utility for teams. Magneton's higher Speed allows it to trap Cawmodore with a Choice Scarf; Zapdos and Cyclohm can serve as much better defensive pivots, with the former having Defog and the latter providing much more important resistances; and Mega Manectric has higher Speed even if Magnezone runs Choice Scarf, as well as access to more powerful Fire-type moves, allowing it to hit much harder. Krilowatt also gives Magnezone competition with its access to more powerful coverage moves and it not being forced to run a Choice item.