Keeping the name out of the title to try to avoid spoiling something in a search.
I think phase 1 is great. Tough but fair, doesn't take too long to learn. Phase 2 isn't the worst thing ever, but with literally every attack being an AOE, there is a ton of visual noise on screen that makes it much harder to see what's actually going on. If you're not staying right in the boss' face, you're going to get hit, and you might still get hit even if you do.
I also really had trouble using fist weapons. They just didn't seem to reach enough and I was missing a lot of hits I thought I should have gotten, which felt a lot less fun. Switched to some stabby s-words with poison to wrap this one up....