Choice Scarf

Boosts Speed, but allows one move. (Hold)

Choice Scarf is probably my favorite revenge killing tool. It boosts your Speed by 50%, letting slower Pokémon outspeed threats they normally couldn't touch. Like all Choice items, you're locked into one move until you switch out.

My favorite strat when using this is Gengar + Trick. Gengar can then outspeed and then give the opponent the restriction of being locked into the first move they use.