I never see the animation for Berserker Strike but it is always in my death recap. I have been hit by this skill from nearly every player I encounter now but it is never visible. I can maybe hear a sound cue, but it's not clear. I figure it is one of these things:
1. The animation is broken and really can't be seen.
2. The animation is so subtle under all of the new techno rave skill animations that it cannot be seen clearly.