Buddha Sacred Mountain Sect Master only had one motive for wanting to kill Luo Yunyang. He wanted to save his dignity, or rather the dignity of the Three Era Supreme Sect's main sects.
It could even be said that the main sect had gone all out in order to prevent Luo Yunyang from becoming a Zongzi. However, even so, Luo Yunyang had still ultimately defeated and killed Sky Origin Zongzi.
Luo Yunyang was only one person, but the damage he could deal to the main sect was massive.
If he was allowed to become a Zongzi, then the main sects of the Three Era Supreme Sect would be absolutely disgraced and their prestige would drop. In the future, controlling the other subsidiary sects would become a thorny issue.
Thus, after hesitating for a moment, this Sect Master had unleashed a powerful attack, blaming it on the name of the Blood Demon.