Mage - What level anger do you get?

[Madstrike]

so anger increases the rage generation by a fixed amount and also percentage? I thought it was only by %, I have not put 1 single point in it since Ive been using the pain skull, and inquisitors to generate rage(Im a mage), however I think of ditching the inquisitors, maybe I should put at least 1 point into anger, but I also need other skills which I consider very important(Frenzy, Heroism, Onslaught), so every might run counts. I have Royal Snakes with the blue dragon, and also a snake boots, so my royal snakes always go first(also have lvl 3 adrenaline if I need to boost their initiative first turn) so I was wondering if 3 points into onslaught is rly necessary over other skills such as frenzy and heroism?