First of all, let me congratulate you on making it so high with such a huge water weakness; you must be one brilliant battler. That brings me to the elephant in the room: water-types. Your team is pretty susceptible to both bulky waters like Crocune, Vaporeon or the accursed Rotom-W, as well as sweepers and wallbreakers like CB/Belly Drum Azumarill , Mega-Gyarados and Keldeo, especially if they form cores with bulky behemoths like Ferrothorn or Mega-Venusaur.
I don't think I need to tell you that Mandibuzz is your (somewhat unreliable) answer to the aforementioned grass-types, which can otherwise spread leech seed and thunder wave as they please. The foul-play counter to Azumarill is also unreliable, as a bulkier bunny can take the hit and proceed to smash through the rest of your team. I tested, and found that Azumarill running 72 HP EVs will not die to +6 Foul Play if SR isn't present. Mandibuzz itself is prone to being taunted or poisoned by faster threats/Prankster users. Rotom-W, even with mimimum SpAtk investment, has a good chance to 2HKO Mandibuzz with Volt Switch after SR, seeing as you aren't running Leftovers.
I suggest a WishProtect Vaporeon:
Vaporeon @ Leftovers
Nature: Bold
Ability: Water Absorb
EVs: 248 HP / 252 Def / 8 Speed
Moveset:
Wish
Protect
Scald
Roar / Toxic / Ice Beam Heal Bell
This Vaporeon is the best answer to opposing water-types, including Keldeo, Azumarill, Greninja and Gyarados. It can take the place of Sylveon as well as Heatran by passing large wishes as well as burning and poisoning opponents (though I feel that toxic does not work well with scald, and roar would be a better way to deal with boosters). Ice Beam is an option.
The only downside is that Vaporeon misses out on some things: It cannot be a cleric Turns out it can learn Heal Bell, so don't bother with Celebi;and it cannot set up hazards. To answer that, I suggest a partner such as Gliscor:
Gliscor @ Toxic Orb
Nature: Jolly
Ability: Poison Heal
EVs: 244 HP / 40 Def / 224 Speed
Moveset:
Taunt
Stealth Rock / Defog
Earthquake
Roost / Knock Off / Toxic
This set, acts as a pivot, maintaining good physical bulk while being fast enough to taunt all common hazard setter except Aerodactyl (which is rare) and also being able to set up its own hazards. It is worth mentioning that Defog is incompatible with Poison Heal, though.
This Gliscor pairs very well with Vaporeon as it can take the electric and physical grass moves aimed at Vaporeon, and can also avoid its water and ice. The last slot is up to you as Roost prolongs longevity while Knock Off eases your team's support. Toxic is an option, but you shouldn't need it if you're running Toxic on Vaporeon.
With this set, I really think you can replace Mandibuzz as well, seeing as Gliscor is immune to toxic (and all status, courtesy of Poison Heal) which really cripples Mandibuzz. Gliscor can also beat Aegislash easily thanks to STAB Earthquake. That leaves you with another option of using Celebi as another partner:
Celebi @ Leftovers
Nature: Bold / Calm
Ability: Natural Cure
EVs: 252 HP / 236 SpD / 20 Speed
Moveset:
Toxic
Heal Bell
Stealth Rock / Recover
Leaf Storm / Giga Drain
This set is an ideal replacement to Sylveon and forms a good core with your team, since Celebi can use Stealth Rock as well as Heal Bell and Toxic alongside a defensive spread to further support the team. Natural Cure allows it to care less about status. Celebi will also handle many all of the water-type threats faced by Scizor by threatening them with an immediate high-powered STAB Leaf Storm or a more consistent Giga Drain.
And lastly, I've seen many trying to tell you to put Iron Head or Poison Jab onto Scarfchomp, but I feel it's redundant. The only relevant fairy-types are Togekiss, Azumarill, Mawile, Sylveon and maybe Gardevoir, of which the two most dangerous take neutral damage from Iron Head. Poison Jab might be situational in always beating Togekiss after SR and standing a good chance to destroy Azumarill at 75%, but bear in mind that Stone Edge does more to Togekiss, whereas Poison Jab does only 10 damage more than a STAB Earthquake to Azumarill. In generall, I think Fire Blast makes a much more useful coverage over Dragon Claw, despite the awkwardness of being stuck using it, as in a situational scenario, it can take out nuisances like Skarmory and Ferrothorn. And I don't recommend using any other dragon type here (including the somewhat hyped Scarf Kyurem-B or CB Dragonite), as they cannot deal with incoming Lati@s or Mega-Charizard X as well as function as a dangerous cleaner and revenge-killer the way Garchomp does.
That's all, and thanks for reading through this lengthy tirade. Personally, I love your choice of MegaScizor, and I use a bulky SD set myself. In fact, thanks to you, I have replaced Superpower with Knock Off on mine, being convinced that it holds more merit in defeating Aegislash and providing support without reducing my stats. If you find this helpful, it was my pleasure.
