However, advancing from the Overlord tier to the Saint tier wasn't an easy task. Otherwise, there would have been an abundance of Saint-tier monsters by then. In order to reach the Saint tier, there were a few more requirements other than level requirement that an Overlord-tier monster had to meet.
It should have attained at the very least a high mastery level of its native element. This was what Gao Peng and Fatty Big Sea were able to find out. The lowest elemental mastery level a monster needed to have in order to advance to the Saint tier was Level 7. Some monsters only had Level 6 mastery over their elements, which was further boosted to Level 7 by their innate traits. Whether this counted as Level 7 still remained to be seen.
Most people had no immediate way of quantifying the traits and abilities of their familiars like Gao Peng. To them, these details were indistinguishable from one another.