Drop one of Tyranitar's offensive moves for Earthquake. While Crunch now hits Steels neutrally, Earthquake is even better for inflicting super effective damage on them. It also bypasses the Attack-dropping effect of Aegislash's King's Shield, since it's not a contact move.
Flash Fire still protects Heatran from Fusion Flare. It's just that its main user, Reshiram, has Turboblaze, a Mold Breaker clone. This lets Reshiram ignore Flash Fire and hit it with its STAB Fire moves.
Sturdy >>>>>>>>>>> Keen Eye on Skarmory. Sturdy guarantees that Skarmory does something at full health. If Skarmory would be KOed at full health, it hangs on with 1 HP instead. It can be restored with Roost. It's also safe to use 252 HP on Skarmory, since its HP isn't divisible by 8 at level 100 (its max HP at level 100 is 334).
44 Speed EVs let Wash Rotom outspeed the occasional Jolly Azumarill, letting it burn Azumarill with Will-o-Wisp before it can do anything.
Edit: This team is seriously screwed over by Fighting Pokemon like Conkeldurr and Breloom (Heatran, Excadrill, Tyranitar and Magnezone are weak to them). Dropping one of those Fighting-weak Pokemon for a Fairy like Sylveon/Clefable or a Ghost like Aegislash would help against this weakness:
Sylveon:
-Wish
-Protect
-Hyper Voice
-Heal Bell/Calm Mind
Nature: Bold
EVs: 252 HP/216 Def/40 SDef
Item: Leftovers
Ability: Pixilate
or
-Hyper Voice
-Psyshock
-Shadow Ball
-Hidden Power (Fire/Ground)/Baton Pass
Nature: Modest
EVs: 244 HP/252 SAtk/12 Spe
Item: Choice Specs
Ability: Pixilate
Clefable:
-Calm Mind
-Moonblast
-Stored Power/Flamethrower
-Soft-Boiled
Nature: Bold
EVs: 252 HP/252 Def/4 SAtk
Item: Leftovers/Life Orb
Ability: Magic Guard
or
-Wish
-Protect
-Moonblast
-Heal Bell/Aromatherapy/Thunder Wave
Nature: Bold
EVs: 252 HP/252 Def/4 SDef
Item: Leftovers
Ability: Unaware/Magic Guard
or
-Stealth Rock
-Moonblast
-Flamethrower
-Soft-Boiled
Nature: Bold
EVs: 252 HP/252 Def/4 SDef
Item: Leftovers
Ability: Magic Guard
or
-Moonblast
-Fire Blast
-Thunder Wave
-Soft-Boiled
Nature: Modest
EVs: 252 HP/4 Def/252 SAtk
Item: Life Orb
Ability: Magic Guard
Aegislash:
-Shadow Ball
-Shadow Sneak/Sacred Sword
-Iron Head/Sacred Sword/Pursuit
-King's Shield
Nature: Quiet
EVs: 244 HP/12 Def/252 SAtk
Item: Leftovers/Spooky Plate/Spell Tag/Air Balloon
or
-Substitute
-Toxic
-Shadow Ball
-King's Shield
Nature: Modest
EVs: 244 HP/12 Def/252 SAtk
Item: Leftovers
or
-Shadow Ball
-Shadow Sneak
-Flash Cannon/Sacred Sword
-Pursuit/Sacred Sword
Nature: Hasty/Naive
EVs: 4 Atk/252 SAtk/252 Spe
Item: Life Orb
or
-Swords Dance
-Shadow Sneak
-Shadow Claw/Iron Head
-Sacred Sword/Head Smash
Nature: Adamant
EVs: 252 Atk/4 SDef/252 Spe
Item: Life Orb