Originally Posted by
Bowshewicz
When the boss uses this ability, I start by moving towards the edge of the room. Normally, the beam doesn't show up right on top of me and I can just follow it as it spins around the room. Get closer in towards the center to catch up if you're falling behind and move towards the edge if you need more space. Should the first beam spawn right where I'm standing, I immediately use a personal defensive cooldown or movement ability to get out of the way ASAP.
Outrunning the beam if it spawns on you is the easiest place to make a mistake in this fight. A better choice is to use a personal defensive cooldown to mitigate the damage, so you can practice not getting hit at all in relative safety.