Wrath Skill right tree "Willpower" ?????

[kamuji]

I cant find any clues about the buff / skill willpower . Its needed to activate the Wrath skill without Rage. Can anybody tell me who can use it and how a berserk can get it ?

I need at least 5 stacks of Willpower. thank you for your help guys

[noctred]

Willpower is the stacking focus buff you gain from typhoon stage 1 (or baseline).