How is my team

I've had Pokemon Diamond for 4 years going on five. My team has changed constantly. Here is the current team I am using

Giratina LV 100 w Luck incense
Ability: Pressure
Shadow Force
Fly
Earth Power
Dragon Breath

Mewtwo LV 100 w Black Belt
SpA of 316!
Ability: Pressure
Fire Blast
Solar Beam
Blizzard
Aura Sphere

Infernape LV 100 w Quick Claw
Ability: Blaze
Rock Smash
Flamethrower
Cut
Strength

Rhydon LV 91
Ability: Lightningrod
Horn Drill
Stone Edge
Earthquake

Heatran LV 91
Ability: Flash Fire
Heat Wave
Lava Plume
Iron Head
Rock Smash

Floatzel LV 90
Ability: Swift Swim
Aqua Jet
Surf
Waterfall
Crunch

If you are going for an offensive Giratina, use this:

Giratina @ Haban Berry
Hasty nature
4 Atk / 252 SpA / 252 Spe

Draco Meteor
HP Fire
Shadow Sneak
Aura Sphere



Mewtwo needs something like this...

Mewtwo @ Life Orb
Timid nature
4 HP / 252 SpA / 252 Spe

Calm Mind
Ice Beam
Thunderbolt
Psychic



Infernape makes a great Choice Bander....however it's defenses are frail to be locked in to a move that will otherwise be resisted by something else being switched in.

Infernape @ Choice Band
Jolly nature
252 Atk / 4 SpD / 252 Spe

Flare Blitz
Close Combat
U-turn
Stone Edge


Rhydon is good for Substitute, because of it's low speed, it can do some scouting for threats. You can go for Swords Dance over Megahorn if you wish.

Rhydon @ Leftovers
Adamant nature
212 HP / 122 Atk / 176 Spe

Substitute
Rock Slide
Earthquake
Megahorn


Heatran is a beast of a special attacker. It's a steel type's worst nightmare. Choice Scarf is the set that makes him shine. Heatran reaches a maximum Speed stat of 417 when wielding Choice Scarf, outspeeding all Pokémon in OU bar Ninjask.

Heatran @ Choice Scarf
Naive nature
252 SpA / 4 SpD / 252 Spe

Fire Blast
Earth Power
Dragon Pulse
HP Electric or HP Grass


Don't use special attacks on Floatzel, as his base special attack is a terrible base 85. Use physical attacks instead.

Floatzel @ Life Orb
Adamant nature
232 HP / 252 Atk / 8 Def / 16 Spe

Waterfall
Ice Punch
Return
Rain Dance

I hope this all helps, I didn't come up with these movesets or EV spreads on my own, I got them all off of Smogon. Go there for more options. :)