I've always been a 1 toon guy, and I do everything with my templar healer. I wanted my own shiny stormproof title, so I did what I could in terms of changing my build so that I could resemble a poor man's dps. The pain I suffered on the last boss was overwhelming - so much so that when I finally did it I slid down my chair in relief and exhaustion. I knew I always had sub-par damage throughout the previous rounds, but I knew whenever I had the mechanics of each down to a tee I would finish it. The boss on round 9 is a whole different story though. There's so many scenarios and mechanics constantly thrown at you, and when one didn't go right it meant death for me. If I didn't get the boss to 70% quick enough in the first section the second Crem would kill me unless I wasted a sigil. Then I needed to make sure and kill the healer before I rose up to the platform so she wouldn't be there when I came back down, which is inconsistent since whenever you start attacking her the second Crem will usually spawn. We then have the second section, where I needed to whiz around on my shards broom with toppling charge and spam harness magicka because the DoT was so strong and the speed of the wall was maxed. And finally, the pure fiesta that is the third section, where my eyes need to be looking at every inch of the arena. For this part I knew 3 Crems would have to spawn before I finished the boss off, so I literally needed to get every single one of the yellow ghosts or I'd die from not being able to kill everything in time. Simultaneously stopping a skele ritual, running like a madman to get ghosts, and checking the boss for his skull move and the must-interrupt move was close to draining my sanity. I finally did it, and it needed one of those runs were it seemed like every situation went in my favour. Being able to stun both the boss and the Crem side-by-side 3 times and dps them at the same with puncturing sweeps was the key to my victory. They say the first time is always the worst and then you begin dying a lot less, but I can tell you now I would die another 100 times doing that boss if I went back again haha. Maybe in the future with a dps character