Drifblim @ Mental Herb
EVs: 252 HP / 4 SpD / 252 Spe
- Disable / Will-O-Wisp
- Baton Pass
Is one of it's best sets in wifi ORAS (NOTE: this is not eligible for most of Smogon tiers as it ignores the evasion clause by having Minimize).
The only differences between this set and your set is that it doesn't have Ominous Wind and Stockpile, because being pretty honest both of them are subpar moves. Destiny Bond is a good move to opt for as well, and can also work very well alongside Unburden.
Substitute and Mental Herb work very well alongside each other, stopping the other Pokemon from Taunt-ing it and helping it set up/pass a free Substitute. Disable can stop many Pokemon from functioning, and Will-O-Wisp can cripple physical attackers. The choice is yours.
Hope I helped!