Is this a good diamond team? what should be my sixth pokemon?

Question

1.Charizard- Air Slash, Heat Wave, Flamethrower, Dragon Pulse.

Blaze, Lv. 67

2.Feraligatr- Aqua Tail, Avalanche, Crunch, Dragon Claw.

Torrent, Lv. 66

3.Sceptile- X- Scissor, Leaf Blade, Night Slash, Earthquake.

Overgrow, Lv. 65

4.Metagross- Psychic, Meteor Mash, Shadow Ball, Brick Break.

Clear Body, Lv. 64

5.Garchomp- Earthquake, Crunch, Dragon Rush, Brick Break.

Sand Veil, Lv. 63, Wide Lens

6. ??

Should i replace my metagross also with one of the pokemon below??

These are the only pokemon i want as my sixth pokemon and fourth which one should i pick???

Rhyperior- Stone edge, Megahorn, Brick Break, Earthquake.

Solid Rock

or

Dusknoir- Shadow Ball, Ice Punch, Dark Pulse, Brick Break.

Pressure, he has high sp. attack

or

Kanghaskan- Dizzy Punch, Shadow Claw, Iron Tail, Brick Break. Scrappy

or

Gengar- Shadow Ball, Dark Pulse, Sludge Bomb, Psychic.

or

Gallade- Psycho cut,night slash,X- scissor,drain punch.

or

Answer 1

dusknoir

Answer 2

pikachu a beast pika piiiii

Answer 3

i suggest gengar

Answer 4

do u have a rotom if u do theres ur answser

Answer 5

gengar