I only need to get close to it to make a fatal blow. [ Despite circumstances and her lowered stats, Saber is still an admirable swordsman and a king as Assassin says. There's a tight grip on the sword lent to her, but she needs two hands if she were to pierce its hide. The rat, however, isn't giving them any time or space to come close to its chest. ]

... Perhaps I can use the other effect of my grail. [ She's not sure if it'll work?! But it's worth a shot. ] If we can get it to open its mouth, the water will do the rest.

[ She actually has not idea if this will work? She has never tried this before. There's a wide tail swipe on the ground and she jumps over it. They only need to wait for an opportunity. ]