Although Master Golden Sword had not yet reached the Nascent Soul Realm, according to Pill Immortal Master's sensing, five years ago, the Golden Sword Lineage of the Liu Yun Sect once again manifested the heavenly changes related to achieving the Golden Core.
As for which disciple achieved the Golden Core, Pill Immortal Master did not check.
Lin Yi believed that the disciple who achieved the Golden Core was most likely his Second Senior Sister Qi Jing Yu, because her character is extremely determined and she goes to great lengths to accomplish what she sets out to do.
After Senior Brother Zhou Yun Feng's foundation was damaged, she delved into alchemy and became the Dan Hall Master within just a few decades.
Latterly, Zhou Yun Feng restored his foundation and achieved the Golden Core, which implies that he has fully let go of the burden weighing on his heart. Coupled with the nurture of love, naturally, the opportunity to achieve the Golden Core emerged.