Infernape
The burning ape is boss at mixed sweeping. You have a lot of possibilities, like the Fake Out offensive Stealth Rock, but this leaves you SubDisable Gengar weak. Instead, let's try an approach of a combinaison of Overheat and Close Combat:
Infernape @ Choice Scarf:
Trait: Blaze
EVs: 252 Speed / 172 SAtk / 84 Atk
Naive Nature
- Overheat
- Close Combat
- Stealth Rock
- Thunder Punch
Stealth Rock offensive lead, with a twist in Overheat. Underestimate it not: even with 172 Atk, you 2HKO Jellicent and Blissey with ThunderPunch and Close Combat, respectively, after Stealth Rock. Overheat and Close Combat together are in one mission: destroy Steel and SkarmBliss. This will also mock Scizor and Mega-Scizor, for info. SkarmBliss won't switch in ease in whatever you throw at them. Blissey wanna not risk the KO by Close Combat, whereas Skarmory's wet paper special defense is holding it back on coming because of Overheat.
Alakazam-Mega
Nope, Alakazam is not gonna work over there. Mega-Alakazam fears Scizor too much, and that's the reason I'm sure it was the cause of your defeats against Scizor and Excadrill. Scarf Excadrill is getting common, so Alakazam is getting hidden by better threats. Its glory hour may have passed. Keep the Mega for something else. Try the frog:
Greninja @ Choice Scarf:
Trait: Protean
EVs: 252 SAtk / 252 Speed / 4 SDef
Modest Nature
- Surf
- Dark Pulse
- Grass Knot
- Ice Beam
Scarf Greninja ? Without U-Turn ? Fear not. I know what I'm telling you to use. Scarf Greninja loses the Protean because getting glued to one move is not attracting, and morover, Greninja's job is to switch typing to sweep, and needs liberty. Then, do you think I'm an idiot ? I am not. Scarf Greninja actually outspeed the whole tier at a comfortable 514 base speed if I am not wrong, and it outspeeds other scarfers, like Excadrill, and can retaliate against them and leave a dent, because of its nice Special Attack when Modest. Dishing in a Specs will render it too slow for doing its job. Greninja outspeeding the tier outspeed can OHKO Excadrill and Specs Latios, which is grand. Anyway, if it doesn't work then try the standard Life Orb Greninja.
Gengar
SubDisable Gengar is arguably the best Gengar nowadays, so try it.
Gengar @ Black Sludge:
Trait: Levitate
EVs: 252 Speed / 252 SAtk / 4 SDef
Timid Nature
- Sludge Bomb
- Shadow Ball
- Substitute
- Disable
Gengar is a to face. It is damn too much annoying to counter it and it can setup on a surprising amount of things. Disable, like its name implies it, disables the last move your foe used, obliging choiced Pokémon to struggle against mighty freakin' adorable Gengar. Now that Shadow Ball is normally effective on Steel, you can safely abuse the dual STAB combination of little Gengar like it has to be done.
Excadrill
Fine.
Sylveon
I've found a true job for pixie: Baton Passing. Really. If you want dual screen, prefer Klefki.
Klefki @ Light Clay:
Trait: Prankster
EVs: 252 Speed / 252 SDef / 4 HP
Timid Nature
- Reflect
- Light Screen
- Toxic
- Foul Play
Foul Play is to avoid being Taunt Bait. Dual Screens is in the skin of your strategy, and Toxic cripple much more than you can think.
Ferrothorn
Now that you have your Stealth Rock Setter, you may want to change Ferrothorn. The Mega can come here, and your choice is wide. I'd recommend Mega-Pinsir simply because it looks, and is boss.
Pinsir @ Pinsirite:
Trait: Aerilate
EVs: 252 Atk / 252 Speed / 4 SDef
Adamant Nature
- Quick Attack
- Frustration
- Swords Dance
- Close Combat / U-turn / Substitute
The best set for Pinsir so far. The choice between Close Combat, U-Turn and Substitute is hard because Close Combat adds coverage, while U-Turn allows scouting and Substitute eases up the setup. Frustration is more swag on a furious beast like Mega-Pinisr, and the happiness should be set to zero. Quick Attack is strong priority.
Hope this helps.
~ Sincerely yours, Blitz of Justice.