Among Chen Yang's current monsters, the Hell Earthwyrm and Red Dragon were both Zifu Disciples, so they naturally wouldn't be able to increase their cultivation.
The ones that were second only to the two demon kings were the Winged Tiger at the intermediate stage of the Demon Venerable Realm, the Light Plucking Eagle at the peak of the early stage of the Demon Venerable Realm, the Fire Crow at the early stage of the Demon Venerable Realm, and the Howling Moon Wolf at the early stage of the Demon Venerable Realm.
Among them, the Fire Crow had relied on itself to cultivate to the early-stage Demon Venerable realm. From this, one could see the strength of the peak Demon King bloodline.
As for the other demonic beasts, other than the Winged Tiger who had broken through to the intermediate stage of the Demon Venerable Realm, the others were still in the same realm as before.