User blog comment:Nekokokokoko/Slane Theocracy's awareness of Ainz/@comment-80.213.121.95-20150919153419/@comment-26836039-20150920170359

Anon is right. They knew Ainz existence even before the events with Clementine and Khajiit. They knew Ainz can control a Death Knight.

If the fake knights also watched the fight between Nigun and Ainz then Slane could have known this too. However this is only an "if". This is because we already know that those fake knights are actually members of Sunlight Scriptures yet Nigun didn't know about Ainz beforehand. This means that those fake knights that Ainz allowed to escape from the clasp of Death Knight run straight back to Slane without reporting to their field commander, Nigun.

About the Windflower Scripture reviving Clementine/Khajiit is still a theory and there's no proof that it happened.