My Suggested Alterations
1: Krookodile needs scarf+Moxie, otherwise good.
2: Name that Tyranitar Darude. please.
3: That flygon is messed up... Try Switching HP and Sdef, but put only 248 in Attk, for 8 in Sdef. also, Fire blast is an option, or in general mixed Flygon...
[email protected]/Sash (If you use Mamoswine, if confused by this, look below.)
Hasty Nature, levitate
252 Spe, 4 SpA, 252 Attk
Fire Blast and rock slide are to provide bonus coverage for Ice, D-Meteor for dragon and damage, EQ for more coverage and STAB, still cannot take Ice shard though...
Or, Throw out Garchomp, make Tyranitar your mega using the Set from the answer below, and replace that Garchomp with Mamoswine. Bulky or Scarf, both always viable...
[email protected]/Scarf/Leftovers (in case you need Flygon to have LO.)
Adamant(Lefties/LO)/Jolly(Scarf/LO) nature. Ability Thick fat
Lets see... Some Ice coverage with both resist and Rock moves, Some nice other ground coverage, along with flying from ice moves. and some Stab to work with flygon from EQ. I personally feel Bulky LO is better, but all are Viable, so your choice.
Also, as a previous answer said, you need rain coverage. So my Recommendation is... Gastrodon. Stoutland or Krookodile to be replaced, but stoutland is less common in Wi-Fi, so keep that one, unless you really like Krook.
[email protected]/Rocky Helmet (Just in case Mamoswine)
Calm Nature, Ability Storm drain
-Hidden power grass
Capable of hitting almost anything water down, excluding Ludicolo which can be taken out with a cleverly used Icicle Crash. Which means... use those two together but Avoid having mamo use EQ. Recover helps for Sustain, Curse and Amnesia provide bonus Defenses, which are needed against things like all grass types and freeze dry users, while Earth power can be used to eliminate things that EQ would hurt team members for. Scald is for burns on evil physical water types, along with some extra coverage for things like most physical attackers, like Sharpedo (so good), Crawdaunt, and I feel as though I forgot some other physical Water sweepers... (Greninja). HP grass is there to finish off anything water type.
May I suggest instead of Krookodile... the dread... Sigilyph maybe, or Aerodactyl, either one really...
[email protected] orb
Bold/Modest/Calm nature, ability Magic guard
252 HP, 252 Def/Sdef, 4 SpA/Def/Sdef
Alright, fairly basic, uses a flying move to get Grass, Stored+Cosmic power, dat power... Roost is just for some extra sustain, and the attack on this thing is amusing after a burn drop.
Aeropostale (Aerodactyl)@Choice scarf/ sash
-Iron head (so much ice coverage...)/Fang move (most any will do.)
-Aerial ace (it needed a flying move.)
-Stone edge/Rock slide
Sash+ Hone Claws+ Stone edge= Success... but, Along with Aerial ace And Iron head for Grass and ice coverage, even though any fang move can be substituted out for that. Rock slide if scarf. EQ is great for scarf.
Hope this long, interesting answer helps. assuming it is interesting.