Sakura and Shirou
Sakura and Shirou both nodded at Nanako's statement, returning to their delicious meal and allowing their guest to do the same. Soon enough, though, the meal was complete and, after tidying everything away, they awaited the girl's demonstration.
Once they were finished, the girl began. They expected some display of magic or, perhaps, some display of physical strength against a nearby object but, instead, to their surprise, all she did was summon up a pair of cross-like gauntlets, which she presumably used for fighting.
However, what came next was even more surprising. The girl waited for a few moments, before her fists suddenly crashed through the table, sending chips of wood flying in their direction. With their battle-toned reflexes, the two of them were able to react quickly enough to ensure no splinters entered areas where they could cause real damage, but nevertheless they could not avoid them entirely, leaving the two of them with several splinters stuck into their exposed skin.
Opening their eyes, they looked at the girl with astonishment, seeing the girl had now lifted the extremely-heavy gauntlets back off the floor, having smashed the table into smithereens and left a huge dent in the shattered concrete underneath. It was clear that the girl had the kind of strength which they had only previously seen in servants and other similar beings.
"Wow, you can lift those?" Sakura asked, amazed. "And even fight with them on? You must be strong...."