[It would be a blow to his pride to allow other Servants to best him because of his size - he finds Archer a rather distasteful individual ("rather difficult and unoriginal," in his own words), but regardless, he gladly crosses blades with the other Servants. He's calm, almost cocky, but at the end of the day his Master seems to be first on his mind at all times. When Tokiomi is nearby, he's fiercely defended. When he stays back, Gilgamesh returns as soon as he can.

When he feels his Master's pull, he thinks to disengage, looks for an opening in the fight, and yet finds himself pulled back with a command spell before long. It doesn't take long for him to realize the grave danger his Master is in, and he doesn't think twice before summoning Enkidu's chains from his gate and using them to bind and yank Kirei away from Tokiomi.

And when he speaks, his voice is even, almost pleasant, but there's an undeniable anger dripping from his words.]

Kirei, do you dare raise a hand against my Master? I'm surprised, I thought you'd know that treachery towards him is treachery towards me, too!