Mine was the one of the last sub-bosses, right before the end. He used blind on me and was casting hell spikes like crazy. Wasn't hard but took a lot more time to kill him than other bosses.
Cornelius, yeah. I think everyone of them uses the same tactic: blind then start using spells. I didn't want to see what spells the intended to use so I killed the first 4 mages right away. Cornelius could cast blind before I struck him, I had to jump arround avoiding his hell spikes. Of course, when the blind wore off, I showed him the errors of his ways...
