In order not to become too estranged from the Temple Alliance, Zhao Guang could only have the Xuanwu Kingdom show its stance.
There's another reason, which is Zhao Guang's concern that the temple might use this opportunity to push him towards the Evil God Temple.
Once they release the news, it will have high credibility. If that happens, the Order Temple faction on the Borick Continent will undoubtedly openly act against him.
Since he's already a demigod, he poses a huge threat.
Moreover, he doesn't believe the people of the Evil God Temple will let him off.
In a situation where both sides are enemies, Zhao Guang would also be very troubled himself. As for joining the Evil God Temple, that is definitely not a good thing for him. Those evil gods don't value training their subordinates.
Their followers are generally manipulated and controlled through various means. Any reasonable person would not want to be caught up in it.
