5. Wear and tear
You know what’s ridiculous about the epic, House of Blue Leaves fight scene in Kill Bill: Part One? It’s not that Beatrix kills roughly a thousand sword-wielding Yakuza while taking barely a scratch. It’s the fact that after demolishing the structural integrity of seven or eight gangsters, she’d have found herself unable to inflict more than a nasty bruise on the rest. Swords, you see, go blunt really fast.
Katanas in particular, being the samurai’s weapon of choice, are not really design for long, protracted duels. Instead, they’re all about short, incredible sharp, one-hit kills, ideally after walking up to someone like a badass and slowly explaining how you’re definitely about to kill them and that there’s nothing they can do about it. Sorry, Mitsurugi, Yoshimitsu, and any protagonist from Onimusha. In real-life, after a few choice cuts you’d be reduced to slapping your opponents to death with a long, steel ruler.