What's this arrow for???
 

What the heck is this arrow for???

Apparently it's a debuff from something =/

If you click on the person there should be a debuff icon with their names...

I've asked a person with that arrow wat it was, but they're not exactly sure either...

Target buff, I think.

With Deeper you are able to see the thing you target no matter what happens, i.e. the ranger hides, or the wizard does the bird thing, or even running behind a tree or a whole mountain.

Only Archers and Fighters get this at 95, but can only be put on pvp or when fighting a mob. And they get Release to take it off or when target dies.