Not sure, seems silly, since there are other sleep inducing moves that they've left alone..>_>
Anyways Ive a better idea now!
Calm - Think ability really matters? Both could be useful..
Will work out ev spread when I finish breeding, but Lefties number with rest going into Defenses, maybe some speed.
Icy Wind
Destiny Bond
Thunder Wave/Will-o-Wisp
Trick/Knock Off
Icy Wind will be perfect if you can predict a switch, lower the speed of whatever comes in, then you can status/item steal(knock off), then switch out accordingly. When it gets to the point where Driffy is close to fainting, Icy Wind the switch again, and use Destiny Bond.
Vaguely gimmicky but I think it could work well if played correctly?
Edit - Sunday - oh yeah..good call. I think the parent I have has it and DB anyways though.