Eos had been holding himself back so that Elgorath would reveal hints about his powers, and he had expected that he would have to bleed and suffer a lot of pain before he could drag out the battle to the extent where he would be able to push Elgorath to the limits.
The purpose of this battle, after learning the truth about the dimension, was not to feed Nyxara any of the Origins of the Ancient Primordials; it never was… it was to check how much he could push against this mysterious force that was deceiving all of Existence.
As it turned out, he did not have to do much. Elgorath had begun using the power of Parallel Realities in front of him, and also moving through the Proto-Dimensions so he could attack.
Even if Eos was not aware of the Proto-dimensions and the true power of the sixth dimensions, with his experience in battle and his understanding of how all the dimensions were supposed to work, he would have quickly known that something here was wrong.
