Yes.. winzip.. he had gladitorial implants put in his brain if you read his fluff as do all zerkers because he spread the Lobo practice of psycho surgery on his legion.. and no its not like the Blood angels Blood rage at all, thats a geneseed defect.
The Fenrisian Helix does heighten their senses to a degree and does make them animalistic thus have the traits of beasts which includes natural savagery (which mankind has proven that human savagery beats natural savagery in destructive potential) but does not facilitate an increase in emotions or any significant difference in the biological function of emotions.
and Gen When i ment wulfen didnt existing i ment Pre-heresy but as you say its in Thousand Sons which i havent read yet. and BTW Ragnar is after the Horus Heresy.
I stand corrected on the Wulfen ( thou not by much) but the rest of my post still stands.
Also to give evidence to WE not being just angry maniacs here's some supporting info on Anger:
"When anger occurs, the body goes instantly into a series of mind-body reactions involving hormones, the nervous system and the muscles. This involves a release of adrenaline which results in shortness of breath, skin flushing, muscle rigidity, and tightening in the jaw, stomach, shoulder and hands. Our thoughts can become fragmented and our eyes may dart from object to object. We become agitated and may even tremble. Our first impulse may be to take action which could turn out to be destructive.
Think of anger as a tool for survival. When we perceive a threat, we experience a fight or flight response.
That is, we will either struggle to avert the threat or we will flee the situation. Either response can be adaptive, depending on the circumstances. Anger is a tool that, when used effectively, can motivate us to solve problems and confront threats in a sensible manner. responses to anger differ greatly as well. Some people are able to experience angry feelings and use them as a way of solving problems rationally and effectively. Others turn their anger inward and engage in self-destructive behavior. Other people strike out when they feel angry. And some refuse to acknowledge their anger – or they confuse anger with other emotions such as vulnerability or fear." - Rita Lehmann, article on Anger- managing a powerful emotion.