From the moment the MC went "it's so heavy", I knew everything related to swords will be uneducated BS. And I was right. WTF is that supposedly correct stance shown by the knight? How do western sword rely on strenght any more than katana? Do the author believe that "westerners" fight by clinking their swords together and pushing each other around like in an 80's Conan the barbarian knock-off?
Those lazy isekai authors should be forced to watch the whole "Ninja operation" film series, with its white mustached men in fluorecent costumes and headbands with "Ninja" written on them.