Many of you probably went in the Slaver's Exile Dungeon where lvl 22 spirit like pain, shadowsong, recuperation, disentchantment spawns almost every places.
Well there's a way to get rid of them permanently.
http://gw.gamewikis.org/wiki/Swap
Just use this 5 energy skills on those spirit and bring them where you want to get rid of them!
Very useful for Duncan since now you don't have to sacrifice the warrior at the top and care about the spirit since now your warrior can tank and bodyblock him, have your full team spam it with skills.
Good luck!