Ye Jin and a few other disciples of the Frozen Cloud sect that had been fortunate enough to see their Patriarch teach himself, knew of his techniques. Or at the very least, they had seen them being used.
The patriarch of the Frozen Cloud Sect, Patriarch Bing was considered to be a genius among his generation. When he was still an inner court disciple he had already started to make his mark and had gathered a lot of merits for the sect.
His progress only increased exponentially and it barely took him two centuries after that to become the patriarch of the Frozen Cloud sect. He was officially the eleventh patriarch of the sect and was considered to be the Second strongest patriarch in all of the Frozen Cloud sect.
He had learned the sect's techniques thoroughly and had even mastered the Forbidden Frost scripture which was consider to be a top level technique that was restricted only to a few people of the sect.