I play Magmortar with Typhlosion, Jynx, and Holon FF. Jason is right, the SW Magmortar is really nice, but the MT one isn't too shabby either. Three for 80 with no consequence is nice. However, I think SW Mag will be the choice because its body is really useful.
Here is my energy line: 1 DRE, 2 Scramble, 11 Fire, 3 Holon FF
Since Mag's real threat is Empoleon, and quick water variants, 3 FFs are enough to effectively eliminate Mag's weakness, which makes it a complete beast to deal with. Watch out for Octillery, though, because it'll discard it.
Typhlosion is better than Blaziken because it has a less detrimental weakness, and its attack discards anything rainbow, DRE, multi like, and that is awesome in the right situation.
I like Jynx over Magnezone. She's much easier to get out, and fits in with the Mentor for Babies and Basics strategy.