With a powerhouse like Fenrir passing down 'judgment' upon them, there wasn't much the Heavenly Moon Sect could do to refute her. Wen Xiulan, under almost any other circumstance, would have never turned over her Cultivation technique to another. However, after witnessing how powerful Fenrir already was, it seemed rather senseless for her to treat it as something sacred. She had already dedicated decades of her life to supporting the Heavenly Moon Sect and, now that she had become the Sect Leader, Wen Xiulan didn't want to see it brought to ruin because of the foolishness of the deceased...
Much like she had stated, Fenrir had absolutely no interest in seizing the Heavenly Moon Sect for herself. After getting a copy of Wen Xiulan's 'Sacred Heart of the Divine Phoenix', she moved to the top of the mountain where Geng Chao previously resided and went into her own seclusion. She did, however, promise to help protect the Sect and, should Wen Xiulan have any issues, Fenrir allowed her to bring the problem to her attention. In truth, her impression of Wen Xiulan wasn't that bad and, much like the women that surrounded her Master, Fenrir could tell she was a good person who cared for others...
Contrary to what Fenrir's expectations may have led her to believe, Wen Xiulan had immediately taken decisive action in order to preserve order within the Heavenly Moon Sect. With some of their more opportunistic disciples choosing to flee after Geng Chao's death, she passed the order to detain them on sight should they reemerge. At the same time, excommunication orders for each member were issued within the circles of other Sects and, if it was found they were harboring former Heavenly Moon Sect members, Wen Xiulan promised divine retribution would descend upon them.
Wen Xiulan was trying to manipulate information to make it appear as though their standing hadn't simply been reduced, but they had instead come under the protection of a more powerful force. It was impossible to prevent word of Geng Chao's and Tian Gengxin's death from spreading, meaning there would certainly be more than a few Sects who would seek trouble with them in the future. By putting on a strong front and taking decisive action, Wen Xiulan wanted to cause these forces to hesitate by making them believe the Sect wasn't weakened but had instead become much stronger.
To emphasize this even further, one of Wen Xiulan's first decisions as Sect Leader was to change the Sect's name to the 'Devouring Moon Sect', with their emblem becoming a wolf's head with a crescent behind it. They had needed to update their Sect tokens so that the various runaways wouldn't be able to claim they were still members, causing their reputation to take a hit if they decided to exploit their former status. To prevent this possibility, Wen Xiulan sent out several messengers and servants to pass her decree to the smaller Sects while giving limited information about what exactly had happened...
In Wen Xiulan's words, the former Grand Elder and the Sect Master had conspired against the student of a powerful Senior named Vahn Mason. As a result, the student had slaughtered both of them but, being a righteous practitioner, she and her Master had become Guest Elders and Protectors of the Devouring Moon Sect. Though Wen Xiulan felt a little cheap, using the name of Fenrir's dead Master to try and scare people, the fear of an unknown Senior who could raise a student capable of easily defeating a Golden Core Cultivator would cause them to exercise extreme caution...
(Fenrir's Commentary: '??? Someone is saying good things about Master...???')