Qin Yu had already gained a thorough understanding of the Golden Core Realm.
From Qi Refining to Foundation Establishment, it is the transformation of spiritual power from gaseous to liquid state, akin to streams gathering into rivers.
To advance from Foundation Establishment to Golden Core, the liquid spiritual power must be refined and compressed countless times until it becomes extremely condensed, finally forming a core.
This process requires a vast amount of spiritual qi as support.
In Qin Yu's estimation, spirit stones are definitely sufficient, and he won't encounter Su Xiyue's situation back then.
He possesses three life runes within his body!
This is also why the consumption of spirit stones is so rapid.
But there was one aspect, unanticipated by him.
During this core formation process... there was a mutation.
He had read records about the Golden Core in the Library Pavilion, and his two mentors had described the entire breakthrough process in detail to him.
