I have come up with 2 sets for Drampa, hope you like them.
Drampa: Holding Sitrus Berry
Evs: 252 Special Attack, 126 Defence, 126 Special Defence
The plan with this set is to get up 2 substitutes and get down to 1/2 HP, activating Berserk. Then using the Sitrus Berry, you'll get back to 3/4 HP so it'll be like you've only used 1 substitute (assuming you've taken no damage in the interim).
High powered Special Attack and it deals with Drampa's weakness to Fighting types
Drampa: Holding Wise Glasses
Nature Modest or Timid (Speed isn't really important but ever little helps eh? Haha)
Evs: 252 Special Attack, 252 HP, 6 Speed
Set up the rain on the first turn and then go to town on your enemies
Strong Special Attack that deals with one of Drampa's weaknesses, and has a 30% chance to confuse the opponent, AND! Never misses if the rain is up
Much like Hurricane, this is a strong Special Attack and has a 30% chance of paralysing the opponent, and never misses if the rain is up
Hyper Voice/Dragon Pulse
Either are strong STAB moves so it's your choice