Dragging myself away from this off topic shenanigans.
I finally got around to doing the arena for real and actually observing the fights.
Honestly speaking? On Dark at least. It's not bad.
When solo.
The PC is going to outscale the hell out of it whenever they introduce another level however. Bleed just remains a bit too strong.
Same with Juice.
But having to reach into the item bag for once in this games life was a neat experience. I hope they improve upon these types of encounters in the future.