The Azure Quetzalcoatl had a good time fighting the strongest Divine. It received a decent power-up from Pesol, who had applied a Soultrait called Guardian Spirit.
It wasn't a high-ranked Soultrait Symbol, but it was powerful nonetheless. Guardian Spirit could only used on other targets if they protected the User from stronger enemies. Since that was exactly what happened – the Divines attempted a few more times to catch up to Pesolt and kill him – the Azure Quetzalcoatl's power increased.
Guardian Spirit increased the target's power by a significant portion of the difference in power between the User and the predator trying to kill the User. The Azure Quetzalcoatl, which was already stronger than the strongest Divine, was thus even stronger and had an easy time burning the Divine. The Divine retaliated with her Soultrait and expanded in size, which also increased her strength.