Ruling Shiftry - Unlucky Wind

[StruckByRain]

"As long as Shiftry is your Active Pokemon, whenever your opponent flips a coin during his or her turn, treat it as tails."

My concern is... "This can't be used to keep a Pokemon asleep can it?"

 

[Craig III]

No, it can't. You flip for Sleep in-between turns when Unlucky Wind has no effect.