User blog comment:B214/Question and Answers 3/@comment-223.196.237.56-20140627153518/@comment-1359322-20140628011736

The Astaroth's trait is unknown. Kankara Formula is unique to Ajuka.

Also as Grendel mentioned, the Bael's POD can trim conscious and souls.

"[……I see. It’s exactly like what that bastard Euclid said. That the demonic-powers carried by the kin of the House of Bael can even trim down the Evil Dragon’s consciousness and soul. This really does work!]"

Not sure if it applies to all, but like Dan said, Rias' POD wasn't strong enough back then. Rias is undoubtedly stronger than most Pure-Blooded Devils of her age and generation, but Riser with more combat experience and demonic powers is stronger than her back then.