Roserade is a Pokemon you must work for. A combo of these moves:
Sludge Bomb (Must Breed Before Episode 13)
Giga Drain (Level Up) / Leaf Storm (Breed)
Extrasensory (Breed)
Sleep Powder (Breed)
Toxic Spikes (Level Up) / Spikes (Breed)
Hidden Power Fire (Keep Breeding until favorable IVs, you can use an IV calculator to determine type. Power is always 60
That's all I can think of at the moment~
The breeding guide which is pinned will definitely help you~
As for ability: Technician is great with Hidden Power, Natural Cure otherwise!