What are your EV spreads?
Anyway, Infernape is better off with a +Speed nature to make the most out of its high Speed:
-Overheat/Fire Blast
-Close Combat
-Grass Knot/U-turn
-Stone Edge/Mach Punch
Nature: Hasty/Naive
EVs: 252 Atk/4 SAtk/252 Spe
Item: Life Orb
or
-Flare Blitz/Fire Punch
-Close Combat
-Stone Edge/Mach Punch
-U-turn
Nature: Jolly
EVs: 4 HP/252 Atk/252 Spe
Item: Choice Band
or
-Swords Dance
-Flare Blitz/Fire Punch
-Close Combat
-Stone Edge/Mach Punch
Nature: Jolly
EVs: 4 HP/252 Atk/252 Spe
Item: Life Orb
or
-Nasty Plot
-Fire Blast
-Focus Blast/Close Combat
-Grass Knot/Vacuum Wave
Nature: Timid/Hasty/Naive
EVs: 4 HP/252 SAtk/252 Spe
Item: Life Orb
or
-Fire Blast/Flare Blitz
-Close Combat
-Hidden Power (Ice)/Stone Edge
-U-turn
Nature: Hasty/Naive
EVs: 108 Atk/148 SAtk/252 SPe
Item: Choice Scarf
Swampert is better off utilizing Choice Band to make its moves more powerful. ChestoRest is one-shot recovery, so it's not advised unless it's on certain Pokemon:
-Waterfall
-Earthquake
-Superpower
-Ice Punch/Stone Edge
Nature: Adamant
EVs: 172 HP/252 Atk/84 Spe
Item: Choice Band
Ability: Torrent
What's the point of using a Mild-natured Hydreigon if it's not mixed? Mixed Hydreigon is an excellent wallbreaker and it can go full-special if it wants:
-Draco Meteor
-Fire Blast
-Superpower
-Roost/Dark Pulse/Earthquake/Earth Power
Nature: Rash/Mild
EVs: 4 Atk/252 SAtk/252 Spe
Item: Life Orb/Expert Belt
or
-Substitute
-Dragon Pulse
-Focus Blast
-Fire Blast/Roost
Nature: Modest
EVs: 4 HP/252 SAtk/252 Spe
Item: Leftovers/Life Orb
or
-Draco Meteor
-Focus Blast
-Fire Blast/Flamethrower
-U-turn/Dark Pulse
Nature: Modest
EVs: 4 HP/252 SAtk/252 Spe
Item: Choice Specs
Shuckle is terrible. No, seriously it is. Its defenses are high, but its HP and offenses are very low and it lacks useful resistances. Ferrothorn and Forretress are the go-to walls here:
Ferrothorn:
-Spikes/Stealth Rock
-Leech Seed
-Power Whip/Protect
-Gyro Ball/Thunder Wave/Protect
Nature: Relaxed
EVs: 252 HP/88 Def/168 SDef
Item: Leftovers/Shed Shell
Forretress:
-Spikes
-Toxic Spikes
-Rapid Spin
-Gyro Ball/Earthquake/Volt Switch
Nature: Relaxed/Sassy
EVs: 252 HP/176 Def/80 SDef or 252 HP/4 Def/252 SDef
Item: Leftovers/Shed Shell
Ability: Sturdy
While Eelektross has a wide move pool, its low Speed lets it down at times. Try out Rotom-W:
-Volt Switch
-Hydro Pump
-Will-o-Wisp
-Pain Split/Hidden Power (Ice)
Nature: Modest
EVs: 184 HP/148 SAtk/176 Spe
Item: Leftovers
or
-Volt Switch
-Hydro Pump
-Thunder Wave/Will-o-Wisp
-Pain Split
Nature: Calm
EVs: 252 HP/28 Def/228 SDef
Item: Leftovers
or
-Hydro Pump
-Volt Switch
-Hidden Power (Ice)
-Trick/Thunderbolt
Nature: Timid
EVs: 4 HP/252 SAtk/252 Spe
Item: Choice Specs/Choice Scarf
While Sigilyph has good Speed, Special Attack and a decent movepool, Reuniclus can do its job of special attacking a bit better, despite being a lot slower:
-Calm Mind
-Psychic/Psyshock
-Focus Blast
-Recover
Nature: Bold
EVs: 252 HP/252 Def/4 SDef
Item: Leftovers
Ability: Magic Guard
or
-Trick Room
-Psychic/Psyshock
-Shadow Ball
-Focus Blast
Nature: Quiet
EVs: 192 HP/64 Def/252 SAtk
Item: Life Orb
Ability: Magic Guard
If you want to keep Sigilyph, it makes a deadly booster with Cosmic Power + Stored Power:
-Cosmic Power
-Stored Power
-Psycho Shift
-Roost
Nature: Bold
EVs: 252 HP/200 Def/56 Spe
Item: Flame Orb
Ability: Magic Guard