[quote=@Lonewolf685]
Considering most of the Masters in that room are female, Zelretch may need to cover that magic mole of his in permenant marker before they tear him apart like Driver Ants on a Sausage fly.
[/quote]

You forget that not all of the female Servants have MR at all, so they can be mesmerized by him if even for a moment at least.

That shall be quite a fun scene, if only because of how chaotic this multiple simultaneous summonings shall be.