After much thought, Gu Ran ultimately attributed the reason to the Blood Crystal Spirit Rice and the Fire Snake Fruit.
Although he had a certain level of confidence in his own aptitude, he did not consider himself one in ten thousand to such an extent that he could surpass a breakthrough that even direct descendants of the Saint Spirit noble families, who needed several decades or centuries to achieve, in terms of talent and aptitude.
Apart from personal factors, the only other reasons he could think of were the Blood Crystal Spirit Rice and the Fire Snake Fruit.
Not to mention the Fire Snake Fruit, after all, he had already consumed three of them in the last two years. Direct consumption was no longer effective, so the other members of the Skeleton King Blessing Contract had to trigger them instead.