Rook Turret

[Ryaz]

I thought the description was clear... when you use a weaponskill on another enemy, the turret switches to that enemy...
/shrug

"Using a weaponskill will cause turret to change targets."

That's the official tooltip description and it's actually poorly worded. If it said it changes to YOUR target, it would be fine. As it is, someone who just got the ability could easily misinterpret it to say it switches to a different target every time a weapon skill is used.