Here's my Firered Team which I moved over to my Diamond Version, some have been bred in Diamond and replaced my Firered Member or have been moved from Battle Revolution. (Pikachu). And they do well in the battle tower. No cheats, hacks, action replay, or anything. Not even a single rare candy, this was all natural.
Charizard
Nickname: Charco
Gender: Male
Level 85
Rash Nature
Specializes in Cool Contest
Hold Item: Charcoal
Attacks:
Blast Burn
Fire Blast
Dragon Rage
Dig
Pidgeot
Nickname: Gee
Gender: Male
Level 84
Serious Nature
Specializes in Cool Contest
Hold Item: Sharp Beak
Attacks:
Brave Bird
Air Slash
Double Edge
Fly
Pikachu
Nickname: Pika
Gender: Male
Level 83
Jolly Nature
Specializes in Cute Contest
Hold Item: Magnet
Attacks:
Volt Tackle
Thunder
Surf
Flash
Gyarados
Nickname: Gyara
Gender: Male
Level 82
Careful Nature
Specializes in Smart Contest
Hold Item: Mystic Water
Attacks:
Hydro Pump
Ice Beam
Dragon Breath
Surf
Victreebel
Nickname: Bell
Gender: Female
Level 81
Sassy Nature
Specializes in Beauty Contest
Hold Item: Meadow Plate
Attacks:
Leaf Storm
Solar Beam
Magical Leaf
Cut
Snorlax
Nickname: Lax
Gender: Male
Level 80
Naive Nature
Specializes in Tough Contest
Hold Item: Focus Sash
Attacks:
Hyper Beam
Giga Impact
Mega Punch
Strength
There you go!