What's the point of Power Trick? Pure Power already makes Medicham strong enough. That, and Medichamite is the superior item for it, since it makes it fast enough to be useful, while giving it more power than Life Orb:
-High Jump Kick
-Zen Headbutt
-Ice Punch/Fire Punch
-Fake Out/Substitute
Nature: Jolly/Adamant
EVs: 252 Atk/4 Def/252 Spe
Item: Medichamite
Ability: Pure Power
Forretress is meh. It's easy bait for Aegislash. Skarmory does the hazard setting better, IMO, as it can force setter-uppers out with Whirlwind:
-Whirlwind
-Roost
-Stealth Rock/Spikes/Brave Bird
-Defog/Brave Bird
Nature: Bold/Impish
EVs: 252 HP/252 Def/4 SDef or 252 HP/16 Def/240 SDef
Item: Leftovers/Rocky Helmet
Ability: Sturdy
or
-Spikes
-Whirlwind
-Taunt/Brave Bird
-Roost
Nature: Bold/Impish
EVs: 252 HP/172 Def/84 Spe
Item: Rocky Helmet
Ability: Sturdy
What's the deal with Substitute on Snorlax? It's not fast enough to take advantage of the status protection it offers. It also doesn't pair well with RestTalk. It's best as an all-out attacker because it's seriously walled by Ghosts:
-Return/Body Slam
-Earthquake
-Crunch/Fire Punch
-Self-Destruct/Wild Charge
Nature: Adamant
EVs: 252 Atk/252 SDef/4 Spe
Item: Assault Vest
Ability: Thick Fat
Sigilyph faces competition from other offensive Psychic Pokemon such as Speed Deoxys, Lati@s, Alakazam and even Gardevoir, as they have more power and/or Speed behind them. This is the best Sigilyph can do:
-Cosmic Power
-Stored Power
-Psycho Shift
-Roost
Nature: Timid/Bold
EVs: 252 HP/16 Def/240 Spe (Timid) or 252 HP/200 Def/56 Spe (Bold)
Item: Flame Orb
Ability: Magic Guard
Sets for Pokemon I mentioned:
Speed Deoxys:
-Psycho Boost
-Ice Beam
-Superpower
-Knock Off/Stealth Rock
Nature: Naive
EVs: 16 Atk/252 SAtk/240 Spe
Item: Life Orb
Latias:
-Draco Meteor
-Psyshock/Thunderbolt
-Defog
-Healing Wish
Nature: Timid
EVs: 252 SAtk/4 SDef/252 Spe
Item: Life Orb
Latios:
-Draco Meteor
-Psyshock
-Thunderbolt/Hidden Power (Fighting)/Earthquake
-Defog/Roost/Recover
Nature: Timid/Hasty
EVs: 4 HP/252 SAtk/252 Spe
Item: Life Orb
or
-Draco Meteor
-Psyshock
-Surf/Hidden Power (Fire)
-Trick/Hidden Power (Fire)
Nature: Timid
EVs: 4 HP/252 SAtk/252 Spe
Item: Choice Scarf
Golurk is outclassed by two other Ghost Pokemon in Gengar and Aegislash. Both hit harder than it, while the former is faster:
Gengar:
-Shadow Ball
-Sludge Bomb/Sludge Wave
-Focus Blast/Thunderbolt
-Destiny Bond
Nature: Timid
EVs: 4 HP/252 SAtk/252 Spe
Item: Life Orb/Focus Sash
or
-Substitute
-Shadow Ball
-Will-o-Wisp
-Disable/Sludge Wave/Sludge Bomb/Focus Blast/Taunt
Nature: Timid
EVs: 28 HP/148 SAtk/20 SDef/252 Spe
Item: Black Sludge
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
or
-Substitute
-Shadow Ball
-Toxic
-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/Spooky Plate/Spell Tag
or
-Swords Dance
-Shadow Sneak
-Iron Head/Shadow Claw
-Sacred Sword/Head Smash
Nature: Adamant
EVs: 4 HP/252 Atk/252 Spe
Item: Life Orb
Only Poison Heal Gliscor can recover off HP when poisoned. Hyper Cutter variants are outright crippled by poison. For your second set, the lack of STAB really hurts and Thunder Fang and Ice Fang are rather weak, considering that a neutral STAB Earthquake outdamages both when super effective:
-Earthquake: 100 (base power) x 1.5 (STAB) = 150
-fang: 65 (base power) x 2 (super effective) = 130
That, and Gliscor isn't that good offensively. It's well-known as one of the best Toxic-stallers:
-Substitute
-Toxic
-Protect
-Earthquake
Nature: Impish
EVs: 244 HP/32 Def/224 Spe
Item: Toxic Orb
Ability: Poison Heal
