You summoned Gilgamesh for the Holy Grail War. How do you prevent him from going rouge.

As OP as he is, I’d feel like his arrogance and hubris would be a double edge sword for his master. Form what I’ve seen in Fate/Zero with Tokiomi, it’s hard as hell to get him to do what you want.

How do you get him to follow you in the war without being killed by him once you try (and fail) to use a command seal?