86 is a pretty good fight. Honestly they had stopped regenerating about then, but I wanted to see if there was another Chain level at either 100 or 120, so I kept going until I got there. They only popped up rarely after the 80's and I had to keep running back to different areas of the mine, and ever other room 5 or 6 would pop back up. I just had to keep avoiding those damn bats.