Yup. It's easy to get overconfident on that fight and come unstuck - didn't help in the second that I forgot to undo my black rites.
A colleague and I have been working on Cerberus ad-hoc at lunch, and as soon as someone drops you end up in a vicious circle because it's impossible to keep him from you for a long enough period of time.
I think it starts lower and works up to 50, but once it's there it stays there.
You can "undo" a black rite in a round? Can you use Lacrima for that within a match?