A paope human is a type of Sennin.
Since Nataku is the only paope human shown being born, most info has to rely completely on him. When he was born, he was encased in a cocoon-like shell. This caused his father to try and kill him before his wife saw it. When the cocoon was torn open, Nataku emerged from it wearing three paope.
A paope human has been shown to be unable to die unless their core is destroyed. The core is at most times stored in their bodies. Because of the core, a paope human can live on even when their body is virtually dead.
Most paope humans are apparently super weapons. They have amazing strength and are able to be saved from any external injury since their core is pefectly fine.