Birth of a new King
There were two people who cared about Rui Fei and were available to save him from the clutches of this demon Qilin San which were Huishe Xiyue and Ji Yao. From where she was Huishe Xiyue could feel the desperate cries of her cub so she dropped everything and flew over.
Because she was now a celestial granted authority by the heavens she was no longer a powerless Huishe female. She had every tool necessary to subdue Qilin San but unfortunately, she didn't get the opportunity to make a grand entrance and save her son.
That is because the most unlikely candidate who was in all aspects at a disadvantage had shown up and did the unthinkable. Who else could this person be apart from Ji Yao?
To fully understand why Qilin San was gasping like he had seen a resentful ghost and stammering, "Im-impossible," we would have to go a couple of minutes back.