Complex sentence: The Baron returns and, enraged, does away with Otto; when he attempts to have the male creature eliminate Nicholas, however, the remnants of his friend's personality rebel and the doctor is killed instead in gruesome fashion.
Split into simpler sentences: The Baron returns and, enraged, does away with Otto. When he attempts to have the male creature eliminate Nicholas, however, the remnants of his friend's personality rebel and the doctor is killed in gruesome fashion.