@1Charak2True enough those are also two solutions but you can still be harmed if either of the two see you dissolving into spirit form leaving you open to an attack so you'd have to pick your spots on when you do it and still gtfo with the masters.

Hmmm... just a heads up, but I really don't think being in Presence Concealment would be that draining on a Master with B rank mana. The Servant also has their own mana pool, and Jack just fed, so I highly doubt Taka is really feeling the burn all that much.

Grail Wars Episode II: Attack of the Mom Jokes

So because I'm not entirely sure of this. Servants have some sort of servant sense thing so they can vaguely sense the presence of other servants that aren't in spirit form/actively hiding? And some sort of similair thing for masters not hiding themselves?

I'll try to post sometime tomorrow. What will likely happen is a hesitant retreat by Assassin. Archer probably will book it soon after. It's too big a variable risk to engage Jack at the current moment for him he probably can tell that it's some sort of noble phantasm.

@1Charak2 Information Erasure ftw