User blog comment:Stbk22/Possible Power up's/Techniques for then new group DxD/@comment-82.40.154.8-20140104102259/@comment-23853100-20140107092436

“Then is that sword really a holy-sword?”

“Yes, it’s one of the holy-swords. It’s not as powerful as the legendary holy-sword I mentioned before, but it’s the real thing. Then it must mean that this man is the holy-sword wielder…… Now I get it. I heard that my predecessor who was in charge of this area vanished, but it would make sense if this was the reason. But if I remember……”

Based on this along i think we can say that the Holy Demonic Sword is stronger since it did break the Fused Excalibur.