If this information spread, then Elder Gao and Elder Yan might suspect him, as only he was the person who had the ability to display this kind of strength.
One way to avoid this was to hide his cultivation realm completely, but there were already some cultivators whom he had left alive, and they had seen his cultivation realm.
He didn't have different masks and robes, so he would be easily identified.
He could argue that his late-stage cultivation realm was fake, but this inheritance site had a limit of peak-stage Core Formation, and even if he was peak-stage Core Formation realm, it didn't justify his strength.
The other way to avoid this was to kill everyone, which he was a little reluctant to do. Although he wasn't a saint, he wasn't a devil either. As long as other cultivators who were not his enemies didn't provoke him, he wouldn't harm them.
