>>17635532I've only faced off against a M-Manectric once in Singles, but I recently did a trade for a shiny max-statted HP Ice one and it's actually a really good Pokemon. I think the main problem is that it LOOKS like shit. If you can get past it looking like a giant lightning bold with legs, then it's very good (with great abilities).
I used to run M-Houndoom a lot (helped with all the Charizard Y's I was seeing). It's not too hard to get in, actually. I'd bait a fire move with my Ferrothorn, get the flashfire boost, Nasty Plot on the inevitable switch, and wreck shit. Mine was Timid with Nasty Plot, Sludge Bomb, Flame Thrower, and Dark Pulse.
I've recently started running M-Ampharos and it's really good as well. I've never faced off against one though. He's bulkier than he looks.