Complex sentence: He is the father of Madame Masque and a frequent enemy of the Avengers, and has also fought Iron Man and the X-Men (playing an important part in the death of Thunderbird) on several occasions.
Split into simpler sentences: He is the father of Madame Masque and a frequent enemy of the Avengers. He has also fought Iron Man and the X-Men (playing an important part in the death of Thunderbird) on several occasions.