Need Suggestions for this team

[Kha'Zix]

Hey there. I'm not new to pokemon but I have very little competitive battle experience. I've only played competitively against a couple of friends in Gen IV but I really never had great team building or synergy. I am open to any team changes.

Sableye @ Lagging Tail
Ability: Prankster
-Trick
-Taunt
-Wil-O-Wisp
-Recover
EVs: 252 HP/120 Def/136 S.Def

Medicham @ Choice Scarf
Ability: Pure Power
-Hi Jump Kick
-Ice Punch
-Trick
-Psycho Cut
EVs: 252 Atk/252 Spe/4 HP

Metagross @ Choice Band
Ability: Clear Body
-Bullet Punch
-Meteor Mash
-Zen Headbutt
-Hammer Arm
EVs: 164 HP/252 Atk/92 Spe

Chandelure @ Life Orb
Ability: Flash Fire
-Fire Blast
-Shadow Ball
-Substitute
-Pain Split
EVs: 252 Sp. Atk/252 Spe/4 HP

Empoleon @ Choice Specs
Ability: Torment
-Hydro Pump
-Surf
-Grass Knot
-Ice Beam
EVs: 200 HP/252 Sp. Atk/56 Spe

Cloyster @ Leftovers
Ability: Skill Link
-Icicle Spear
-Spikes
-Surf
-Rapid Spin
EVs: 248 HP/84 Atk/176 Def

I was thinking of replacing Cloyster for a more reliable wall. Plus, my team could use a cut down on Ground Type weaknesses. Was thinking of replacing Cloyster and Metagross for more speed and resistance.

 

[PlatinumDude]

Medicham is mediocre in OU play because while it has great Attack courtesy of Huge Power, its average Speed lets it down. While Conkeldurr is a lot slower than Medicham, it has good enough defenses to compensate:
-Bulk Up
-Drain Punch
-Mach Punch
-Ice Punch/Payback/Stone Edge
Nature: Adamant
EVs: 120 HP/252 Atk/136 SDef
Item: Leftovers
Ability: Guts

or
-Drain Punch
-Mach Punch
-Facade/Ice Punch
-Payback
Nature: Adamant
EVs: 128 HP/252 Atk/128 SDef
Item: Flame Orb/Toxic Orb
Ability: Guts

or
-Substitute
-Focus Punch
-Mach Punch
-Stone Edge/Payback
Nature: Adamant
EVs: 252 HP/252 Atk/4 Spe
Item: Leftovers
Ability: Iron Fist

In a similar vein to Medicham, Chandelure suffers from average Speed. Gengar or Volcarona are faster alternatives:

Gengar:
-Substitute
-Shadow Ball
-Focus Blast
-Disable/Thunderbolt/Hidden Power (Fire)/Pain Split
Nature: Timid
EVs: 4 HP/252 SAtk/252 Spe
Item: Black Sludge/Life Orb

or
-Substitute/Protect
-Shadow Ball
-Focus Blast
-Hidden Power (Fire)
Nature: Timid
EVs: 4 HP/252 SAtk/252 Spe
Item: Black Sludge/Life Orb

Volcarona:
-Quiver Dance
-Fire Blast
-Bug Buzz
-Hidden Power (Rock/Ground)/Psychic
Nature: Timid
EVs: 252 SAtk/4 SDef/252 Spe
Item: Life Orb/Lum Berry

or
-Quiver Dance
-Fiery Dance
-Bug Buzz
-Roost
Nature: Timid
EVs: 240 HP/252 Def/16 Spe
Item: Leftovers

or
-Quiver Dance
-Fire Blast/Fiery Dance
-Bug Buzz
-Rest
Nature: Modest
EVs: 160 HP/236 SAtk/112 Spe
Item: Chesto Berry

I agree that Cloyster needs to go. Forretress makes a better Rapid Spinner, and you're in a dire need of hazards here:
-Spikes/Stealth Rock
-Rapid Spin
-Volt Switch
-Gyro Ball/Hidden Power (Ice)
Nature: Relaxed/Bold
EVs: 252 HP/252 Def/4 SDef
Item: Leftovers/Shed Shell
Ability: Sturdy

or
-Spikes
-Stealth Rock
-Gyro Ball
-Explosion
Nature: Brave
EVs: 252 Atk
Item: Custap Berry
Ability: Sturdy

Given my suggestion of Forretress, you have too many Steels. A Dragon of your own might be ideal here, such as Dragonite, Hydreigon, Lati@s or Salamence. One can go over Empoleon.