Board Thread:Questions and Answers/@comment-4598697-20150525022512/@comment-25936606-20150525075402

Well if you want to be realistic, I'd say that both would be as random as any other genes.

If we're still in fairytale land, they'd live as long as their story requires, and similarly have the magic that is required for it, unless you, the creator, have some specific plot concept to create drama in the character's life.

I agree with DoD that the strength of power would depend on whatever else they are a hybrid of, but any weakness of power most likely would not show until later in the family if their descendants are hybrids as well. But that would also depend on the type of magic, which could lead into some serious worldbuilding stuff that we, as the fans, may not have the power/ability to decide on.