[Had he been brought from his own world's destruction in his Archer form, it's likely this would have devolved into an immediate threat of death, but... Gilgamesh has a little more restraint than that as a Caster class Servant. So, he merely narrows his eyes, giving Church a look that would cause most men's blood to run cold.]

I will ignore your ignorance this time, but I would advise that you hold your tongue, mongrel, and continue your work.