There is a wide gap between being useful and being dominant. Considering what the berserker has to give up compared to spellbreaker, the fact that it can be kited, and the fact that only a stupidly glassy build that dies if you sneeze on it can get that kind of damage, I fail to see how this could be considered "dominant". Now, if they make the rest of berserker good, I don't care if they nerf arc divider's damage, but as it is now, that's all it really has going for it compared to core and spellbreaker. You nerf that without changing anything else and it's going to be even worse than it was before the rework.