So I'm on my first playthrough of Witcher 2 (which I started a while ago). I recently started the 3rd chapter in Loc Muinne; I'm playing on hard and I have put most of my skill points into swordsmanship and alchemy.

I have a question though: how am I supposed to trigger berzerk mode, once the adrenaline bar is full? I have unlocked both berzerk and group finishers and the group finishers work on pressing 'X' when the bar is full. However, it doesn't seem clear how to trigger berzerk mode, or how I can choose between triggering berzerk or the group finishers.

Also, the description for the 'Mutant' ability says it should allow generation of adrenaline when Geralt is 'intoxicated'. I assume that is supposed to mean when my toxicity bar is full from drinking potions? However, I tried drinking potions to max out the toxicity, but didn't notice the adrenaline bar increasing at all.

Both the game and manual seem to give very minimal details about how these mechanics work. They also seem to be very short on details of what the potion toxicity is supposed to do in the first place. I assume there should be some sort of negative effect, if toxicity exceeds the limit indicators on the bar?

I'm very confused and would love for someone to enlighten me!

I hope you've found out by now... You chose the two abilities that I haven't seen myself in the game (I went for Heliotrope), but they are supposed to be activated simultaneously as soon as you press X. Since the berserk effects are all passive, are you sure they didn't activate at the same time as the group finisher?

There's this Youtube video where two adrenaline skills are activated at the same time (heliotrope and berserker), but it contains SPOILERS from a quest near the very end, so watch at your own risk: https://www.youtube.com/watch?v=YWirRpk0B3k