Is my current team good enough for Cynthia? If not, what could be better?

[Kathylikestoread]

I keep on losing to Cynthia, here's my team:
- Empoleon (Level 64)
Moves:
Avalanche
Drill Peck
Hydro Pump
Flash Cannon

- Rapidash (Level 60)
Moves:
Fire Spin
Smart Strike
Fire Blast
Flame Charge

-Roserade (Level 60)
Moves:
Sludge Bomb
Dazzling Gleam
Petal Blizzard
Bullet Seed

-Luxray (Level 63)
Moves:
Iron Tail
Crunch
Shock Wave
Spark

-Staraptor (Level 62)
Moves:
Aerial Ace
Steel Wing
Close Combat
Fly

Dialga (Level 50)
Moves:
Roar of Time
Ancient Power
Slash
Flash Cannon

 

[Handium]

in general, try to get that Dialga around the level of the rest of your team along with adding some status moves like thunder wave, swords dance or other things
Cynthia is 60-66 level wise with items, IVs and EVs
Status moves are key as well as switching.

You’ll want to level up Dialga to level 64 to gain access to Aura Sphere and Power Gem to replace Slash and Ancient Power

Grab Swords Dance and Work Up from Veilstone department stone as well, you’ll want that on Empoleon and any ‘mon you want
This makes it easier to beat Cynthia

Roserade can’t do anything against Dialga so it’s a very safe switch

I’ve never played BDSP so just general stuff

 

[RichestAirPirate]

I keep on losing to Cynthia, here's my team:
- Empoleon (Level 64)
Moves:
Avalanche
Drill Peck
Hydro Pump
Flash Cannon

- Rapidash (Level 60)
Moves:
Fire Spin
Smart Strike
Fire Blast
Flame Charge

-Roserade (Level 60)
Moves:
Sludge Bomb
Dazzling Gleam
Petal Blizzard
Bullet Seed

-Luxray (Level 63)
Moves:
Iron Tail
Crunch
Shock Wave
Spark

-Staraptor (Level 62)
Moves:
Aerial Ace
Steel Wing
Close Combat
Fly

Dialga (Level 50)
Moves:
Roar of Time
Ancient Power
Slash
Flash Cannon

Okay so assuming this is BDSP, I can safely say that no. This team is not Cynthia material. In fact, I'd even say that these movesets REALLY could use some work. I don't wanna say they're bad, just FAR from ideal.

Empoleon's moves are fine. I would replace Avalanche with Ice Beam though. The TM for it is in the Veilstone department store. You could maybe replace Drill Peck with something like Work Up.

Rapidash's moveset is pretty rough. I would replace Fire Spin with Poison Jab if you have a TM (you can get the TM for it on route 212's rainy area behind a tree, in the middle of the square of logs and bridges. You need to surf though) to spare or Megahorn if you have a Heart Scale. Also, reach level 63 to learn Flare Blitz to replace Flame Charge.

Roserade... oh man. Ditch Bullet Seed in favor of... whatever else. I'd say get an Energy Ball TM but that's locked to Underground merchants, so try to go for Giga Drain via Heart Scale or TM (you can get one in the Bogsunk Cavern or Route 209 between the trees south of hallowed tower. You'll have to surf though.) Or teach it Petal Dance via Heart Scale. Petal Blizzard could also get dropped in favor of something like Toxic.

Luxray's a weird Pokémon. It already has a trash movepool (WHY IS WILD CHARGE AT LEVEL 80?!) so you're really gonna have to make the most of it. Iron Tail probably ain't worth it. I'd probably replace it with Thunder Wave (if you have heart scales) for support and drop Shock Wave for Volt Switch (the TM is in Amity Square) for utility, I guess. But in general, Luxury is just... kinda bad. You can still use it! But you will really have to try to make it work with its awful movepool...

Staraptor's moves are mostly fine. Dunno why you don't have Brave Bird though. I would've replaced Fly with it. I think that dropping Aerial Ace for U-Turn could be good utility too.

Dialga though? Dude, grind that Dialga. Cynthia's got a squad of level 60-66 Pokémon, and you coming in with a level 50?! No wonder you're losin'! At level 56, Dialga gets Aura Sphere. And at level 64, it gets Power Gem. And it gets a very large TM movepool.