You need to have a talent called Hysteria in blood, which you can put on a person in your party. This talent gives him a 20% dmg increase for 20(?) sec. Now the funny part is, it also makes him lose 1% of his hp each second.
Duel your friend which is in your party(!). Win the duel, and be quick to put hysteria on him. Watch your party member rage while he dies of the hysteria dot!
by olaloken