While Galvantula seems tempting, it's not that good because its frailty means it has a hard time setting up Sticky Web multiple times in a match. If a Defogger wipes away Sticky Web and Galvantula has been KOed, you won't have a second chance to get it up again. This is why Shuckle is a better Sticky Web user, as it has the bulk to set up Sticky Web again when needed:
-Sticky Web
-Stealth Rock
-Encore
-Infestation/Toxic/Knock Off
Nature: Bold/Impish
EVs: 248 HP/252 Def/8 SDef
Item: Mental Herb
Ability: Sturdy
Sigilyph isn't that good in OU either. It has an awkward Speed tier, meaning it's outsped by the many base 100 Speed Pokemon in OU (sure, you have Sticky Web to help out, but still...). Mega Gardevoir or Mega Gallade are possible Mega Psychics you can use:
Gardevoir:
-Psyshock
-Hyper Voice
-Focus Blast
-Taunt/Will-o-Wisp/Calm Mind
Nature: Timid/Modest
EVs: 24 Def/232 SAtk/252 Spe
Item: Gardevoirite
Ability: Trace
Gallade:
-Swords Dance
-Zen Headbutt
-Close Combat
-Knock Off
Nature: Jolly
EVs: 4 HP/252 Atk/252 Spe
Item: Galladite
Why are you using Shock Wave on Magnezone? The fact it never misses isn't much of a reason because Shock Wave is still very weak. Volt Switch is the move to use, as it lets Magnezone gain momentum by switching out and dealing damage:
-Thunderbolt
-Volt Switch
-Flash Cannon
-Hidden Power (Fire)
Nature: Modest
EVs: 172 HP/252 SAtk/84 Spe (outspeeds min Speed Skarmory)
Item: Choice Specs
Ability: Magnet Pull
Salamence is terrible in OU now because pretty much every Dragon out there does its job much better. These include the Latis, Dragalge and Dragonite:
Latias:
-Draco Meteor
-Psyshock/Hidden Power (Fire)
-Defog
-Healing Wish
Nature: Timid
EVs: 72 HP/184 SAtk/252 Spe
Item: Life Orb
Latios:
-Draco Meteor
-Psyshock
-Hidden Power (Fire)/Earthquake/Roost
-Defog/Roost
Nature: Timid
EVs: 4 Def/252 SAtk/252 Spe
Item: Life Orb
Dragalge:
-Toxic Spikes
-Sludge Wave
-Draco Meteor
-Focus Blast
Nature: Modest
EVs: 228 HP/252 SAtk/28 Spe
Item: Black Sludge/Draco Plate/Dragon Fang
Ability: Adaptability
or
-Toxic Spikes
-Sludge Wave
-Draco Meteor/Dragon Pulse
-Scald
Nature: Calm
EVs: 248 HP/232 SDef/28 Spe
Item: Black Sludge
Ability: Adaptability
or
-Sludge Wave
-Draco Meteor
-Focus Blast/Hidden Power (Fire)
-Scald
Nature: Modest
EVs: 228 HP/252 SAtk/28 Spe
Item: Choice Specs
Ability: Adaptability
Pangoro needs Superpower if it wants to break through stuff like Mega Sableye, which can survive a Drain Punch:
-Superpower
-Knock Off
-Gunk Shot
-Ice Punch/Parting Shot
Nature: Adamant
EVs: 4 HP/252 Atk/252 Spe
Item: Life Orb/Choice Band
Ability: Scrappy
Nidoking isn't a bad Pokemon by any means, but it's horrifically outclassed by Incarnate Landorus simply because its Earth Powers are much stronger than Nidoking's. It's also faster:
-Rock Polish
-Earth Power
-Hidden Power (Ice)
-Sludge Wave/Knock Off
Nature: Modest/Rash
EVs: 4 Def/252 SAtk/252 Spe
Item: Life Orb
Ability: Sheer Force
or
-Earth Power
-Sludge Wave/Knock Off
-Focus Blast/Stealth Rock
-Hidden Power (Ice)
Nature: Timid/Naive
EVs: 4 Def/252 SAtk/252 Spe
Item: Life Orb
Ability: Sheer Force
or
-Calm Mind
-Earth Power
-Focus Blast
-Psychic/Hidden Power (Ice)
Nature: Timid
EVs: 4 Def/252 SAtk/252 Spe
Item: Life Orb
Ability: Sheer Force