The Heavenly Dao Ranking was a ranking established by the Heavenly Dao Sacred Academy. As the saying went, the heavenly dao is so lofty that it is unreachable.
There's only a total of ten positions in this ranking. Age was not an issue but every one was from the Mystic Region. These ten people were the ten people most likely to comprehend the heavenly dao and become a heavenly deity of the Mystic Region. From this, one could very well imagine the weightage of this ranking.
From another perspective, this ranking was a measure of one's potential in reaching the heavenly deity realm. For those who managed to be ranked, they were publicly believed to have the greatest chance to become a deity, entering a higher realm. Age was irrelevant, and current strength also wasn't a criteria. For example, the rankers on the Heavenly Dao Ranking might not be the most powerful figures in the world overlord realm and there might be many who could defeat them. But even so, their names were still on the ranking. The only reason for this was because their potential to become a heavenly deity was greater than the others, despite the fact that they are currently weaker. Naturally, it was said that strength wasn't a criteria but in truth, every ranker on the rankings was at the world overlord realm. After all, if one couldn't even become a world overlord, what qualifications do they have to say that they can become deities? But even so, for some geniuses of the junior generations who displayed startling talent despite the fact that they are not at the world overlord realm yet, they would still have a chance to become one of the ten rankers. Hence, the rankings would occasionally be updated as people inside might be replaced.
In the original Heavenly Dao Rankings, there are two disciples from the Ziwei Divine Court, two disciples from the Great Devil Divine Palace, a disciple from the Heavenly Deity Mountain, three members of the Heavenly Dao Sacred Academy, and as for the last two, they are not from any major powers.