My team

[mrpopo1701]

I'm new to PC and sort of new to competitive pokemon battles and i need help building my team. My team in pokemon X consists of:
Forretress, impish, sturdy, Rocky helmet, Gyro ball - Explosion - stealth rock - Toxic spikes
Tyranitar, Adamant, Sand stream, Tyranitarite, Aerial Ace (want to switch to chrunch) - fire fang - EQ - Stone edge
Metagross, naughty, clear body, none, EQ - Meteor mash - Zen headbutt - Bullet Punch
Gengar, Mild, Levitate, Gengarite, Psychic - Dark Pulse - Energy Ball - Hex
Rotom-wash, Modest, Levitate, Chesto berry, Hydro Pump - Rest - Thunderbolt - Will-O-Wisp

These are my pokemon that i have in my competitve party and am looking for some sugestions on what i could use for a last pokemon. I am open for anything like items, move changes, anything to help.
~Josh Varela

 

[PlatinumDude]

EVs for each team member would be appreciated.

Forretress isn't worth it anymore. It's setup bait for a lot of things such as Aegislash, which walks all over it. Other hazard setters like Ferrothorn and Skarmory are better in its place because they have ways to discourage setup:

Ferrothorn:
Ferrothorn:
-Leech Seed
-Protect/Thunder Wave
-Gyro Ball/Power Whip
-Stealth Rock/Spikes/Gyro Ball
Nature: Relaxed
EVs: 252 HP/216 Def/40 SDef
Item: Leftovers/Rocky Helmet
Ability: Iron Barbs

or
-Stealth Rock/Spikes
-Leech Seed
-Gyro Ball/Thunder Wave
-Power Whip/Protect
Nature: Relaxed
EVs: 252 HP/216 Def/40 SDef
Item: Leftovers/Rocky Helmet
Ability: Iron Barbs

Skarmory:
-Whirlwind
-Roost
-Stealth Rock/Spikes/Brave Bird
-Defog/Brave Bird
Nature: Impish
EVs: 252 HP/252 Def/4 SDef or 252 HP/16 Def/240 SDef
Item: Leftovers/Rocky Helmet
Ability: Sturdy

Mega Tyranitar should use Dragon Dance; it has the Speed to actually take advantage of the +1 Speed boost. With a Speed boost, Jolly Mega Tyranitar outspeeds threats up to Greninja. Going defensive with it isn't a good idea because it lacks Leftovers to steadily heal itself; its defensive typing isn't the best, either:
-Dragon Dance
-Stone Edge/Ice Punch
-Crunch/Ice Punch
-Earthquake
Nature: Jolly
EVs: 252 Atk/4 Def/252 Spe
Item: Tyranitarite
Ability: Sand Stream

Metagross isn't cutting it anymore. It's pretty much outclassed by Aegislash because it hits harder:
-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/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/Sacred Sword
-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

A Timid nature is ideal for Gengar because it risks getting outsped by things like Mega Pinsir and Mega Gardevoir with a Mild/Modest nature. Why'd you opt for Dark Pulse over Shadow Ball, for instance? Dark and Ghost have the exact same coverage, so the rule of thumb is to go to the move that gets STAB; in that case, use Shadow Ball. Also, Hex is weak and gimmicky; it relies on a statused opponent to be effective:
-Substitute
-Shadow Ball
-Will-o-Wisp
-Disable/Sludge Bomb/Sludge Wave/Focus Blast/Taunt
Nature: Timid
EVs: 28 HP/148 SAtk/80 SDef/252 Spe
Item: Black Sludge

or
-Shadow Ball
-Sludge Bomb
-Focus Blast/Thunderbolt
-Destiny Bond
Nature: Timid
EVs: 4 HP/252 SAtk/252 Spe
Item: Life Orb/Focus Sash

Make Wash Rotom Bold with 248 HP/216 Def/44 Spe (in other words, re-breed it). This lets it take hits from Talonflame and Mega Pinsir better. Also, Volt Switch > Thunderbolt for the scouting utility.

 

[mrpopo1701]

Thank you for the feedback it is very appreciated. I will look into replacing fortress,( i just obtained a farroseed) and re-breed my T-tar to jolly, also i will change up my gangar i just used him because he was shiny. I am still looking for a last member to add to my team too. Thank you very much.