The tree and the sword
The trick mentioned by the gorilla was something that is of common knowledge in Divine Firmaments, as Eris and Mylene had already told Aster, there are mortal realm cultivators and even normal people living in the Divine Firmament.
Otherwise, who would do the manual work for those exalted people that had broken through the Mortal realms, the same applied to spirit beasts, there were "weak" spirit beasts that got strong after maturing.
And among spirit beasts, there are races whose names change after evolving, just like Charlotte and Natasha, people who have the capacity to tame spirit beasts exist and this trick is something that those with that ability discovered.
When a spirit beast makes an oath, they can use their race as not all of them "know" their name, or have one even, that used to be what people believed.