How are Kane and The Undertaker half brothers?

Answer 1

In 1997, Paul Bearer brought Kane to the WWE ( then WWF ) to challenge the Undertaker.

It was revealed that he was the Half-Brother of the Undertaker, and later on that Paul Bearer is Kanes father.

Answer 2

They are half brothers. I know this because on the DVD set "undertakers deadliest matches." He says that Paul Bearer was the father of undertakers half brother Kane.

Answer 3

yes