Ybur actually wasn't as weak as it appeared.
Because when it previously collapsed, it secretly consumed a Body Secret Source, allowing its injuries and exhaustion to rapidly recover.
Of course, this was mainly because it was a Slime, with a highly malleable body that healed quickly; any other species wouldn't have such a swift recovery rate.
...This elf must also be a Fourth Rank Demonic Warrior, and normally a Fourth-Rank Demonic Warrior could only execute movements as tumultuous as the tide three times a day, after which, unless the opponent also consumed a Mysterious Source, they wouldn't be able to burst forth with such movements again! So, it was finally time to compete on an even playing field!
Ybur was exceptionally excited, feeling that it had finally survived the worst.