Black Cat:
Finally, someone useful. Go meet with Klaus. He came the closest, out of all the challengers. I head that he's wasting his time fishing and drinking in Goddard Castle Town after failing the challenge and becoming a wreck like me. He'll help you with the first clue about the forbidden power. Try to make my dream come true this time.
Also, this is what I've written down about the monster that crippled me, so it will be helpful for you to read.
Now, don't even think about coming back until you have that power in your hand!