And here it is, the fight I've heard so much about, the archer that could truly keep up with, if not maybe surpass, Gilgamesh. Honestly I'm surprised Gil's ocular Noble Phantasm, Sha Naqba Imuru, didn't inform him on True Archer's powers, or Gil would know that True Archer's defenses more than hold off the majority of the Gate of Babylon.
And as of reading this chapter, I'm surprised Gil doesn't recognize him (I do recognize him since I was spoiled long before I decided to give this manga a read).