A Calm nature is bad for Ferrothron, as it's a physical attacker. As a mono-attacking move, Power Whip is preferred because of its higher PP than Gyro Ball. Ferrothorn's EV spread below gives it good mixed bulk, letting it take physical and special hits comfortably:
-Stealth Rock
-Leech Seed
-Power Whip
-Gyro Ball/Protect/Knock Off
Nature: Relaxed
EVs: 252 HP/88 Def/168 SDef
Item: Leftovers
Ability: Iron Barbs
Jolly > Adamant on Scarf Tyranitar, as with Adamant, it fails to outspeed Garchomp and those faster than it, even with Choice Scarf. Pursuit is preferred over Ice Punch because of the utility of catching opponents as they switch.
Why would you use Scope Lens on Talonflame? It doesn't have any high critical hit ratio moves to abuse with said item. Adamant is also the preferred nature for it, as Gale Wings gives Brave Bird priority, making the extra Speed from Jolly unnecessary. Talonflame also isn't very strong, so it needs all the power it can get:
-Swords Dance
-Flare Blitz
-Brave Bird
-Roost/Natural Gift
Nature: Adamant
EVs: 252 Atk/4 Def/252 Spe
Item: Life Orb/Sharp Beak/Sky Plate/Liechi Berry/Salac Berry
Ability: Gale Wings
or
-Flare Blitz
-Brave Bird
-U-turn
-Roost/Tailwind
Nature: Adamant
EVs: 252 Atk/4 Def/252 Spe
Item: Sharp Beak/Sky Plate/Choice Band
Ability: Gale Wings
or
-Bulk Up
-Brave Bird
-Roost
-Taunt/Will-o-Wisp
Nature: Careful
EVs: 248 HP/8 Def/252 SDef
Item: Leftovers
Ability: Gale Wings
Swords Dance + King's Shield Aegislash is tempting at first glance, but it's terrible. It's shut down by burn easily and very easy to wall. Aegislash is better off going mixed, special or without King's Shield if it uses Swords Dance:
-Shadow Ball
-Shadow Sneak/Iron Head
-Sacred Sword/Iron Head/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/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
Greninja needs Extrasensory so that it can deal with Mega Venusaur (Thick Fat makes Ice Beam a neutral move on it). Hydro Pump > Surf for the extra power; Greninja needs all the power it can get:
-Hydro Pump
-Ice Beam
-Extrasensory
-Dark Pulse/Hidden Power (Grass/Fire)/Grass Knot/Spikes
Nature: Timid
EVs: 4 HP/252 SAtk/252 Spe
Item: Life Orb
Ability: Protean
Jellicent is terrible now because Knock Off is omnipresent. Its spin blocking role has been diminished, since there's an alternative hazard-clearing move in Defog. Rapid Spin/Defog support is needed, as Talonflame is weak to Stealth Rock. Mandibuzz, Zapdos and Mega Scizor are bulky Defog users to fall back on:
Mandibuzz:
-Foul Play
-Roost
-Taunt/Whirlwind
-Defog
Nature: Bold
EVs: 248 HP/136 Def/108 SDef/16 Spe
Item: Leftovers
Ability: Overcoat
Zapdos:
-Thunderbolt
-Roost
-Defog
-Heat Wave/Toxic/U-turn
Nature: Bold
EVs: 248 HP/168 Def/68 SAtk/20 Spe
Item: Leftovers
Mega Scizor:
-Bullet Punch
-U-turn/Superpower/Knock Off
-Defog
-Roost
Nature: Impish
EVs: 248 HP/252 Def/8 SDef
Item: Scizorite
Ability: Technician
Goodra is rather meh, but it could work. However, there are better moves to be used:
-Draco Meteor
-Fire Blast
-Thunderbolt/Sludge Bomb
-Dragon Tail
Nature: Quiet/Modest
EVs: 248 HP/252 SAtk/8 SDef
Item: Assault Vest
Ability: Gooey/Sap Sipper
Conkeldurr is one of the best Assault Vest users because of its access to semi-reliable recovery in Drain Punch:
-Drain Punch
-Mach Punch
-Knock Off
-Ice Punch/Stone Edge
Nature: Adamant
EVs: 252 Atk/236 SDef/20 Spe
Item: Assault Vest
Ability: Guts
If you specifically wanted a special wall on the team, use Mega Venusaur:
-Giga Drain
-Sludge Bomb
-Leech Seed/Sleep Powder/Hidden Power (Fire)/Earthquake/Knock Off
-Synthesis
Nature: Calm/Sassy
EVs: 252 HP/240 SDef/16 Spe
Item: Venusaurite