I'm sorry, man. That sword design is just shit... Impractical as hell given that arms don't float without bones and don't allow objects to phase through it.
Patent-making do be crazy with the tech shown in this... She can probably become the richest person given how many things in the modern world she could think of.
I mean, for world building this is already pretty great. I mean, when was the last time reincarnated characters have basically lived all of both lives?
I've seen way too many of the "ancient worlds turning out to be post-apocalyptic worlds" genre now. Like c'mon why not have it just be something else not birthed from human tech??