Depends. He was one of the original members of the Brotherhood of Evil Mutants. He has been in X-Factor. He is a member of the Avengers, and he is a member, by marriage (although he and his wife are separated) of the Inhumans.

no, she went on as a member of the brotherhood of evil mutants.

The Pythagoreans brotherhood members were followers of the philosopher-mathematician Pythagoras. I don't exactly who though.

Many groups claim to be a brotherhood for their members.

A brotherhood implies the group is all males.

depends on which comic or movie/ tv show your talking about. but, the main enemies are magneto, the brotherhood of mutants, and apocalipse. hope this helped.