Talk:Warrior Takemikazuchi/@comment-28085708-20160602022326/@comment-27168967-20160602170442

There's actually two types of katana. The first is the one we are more accustomed to seeing, the curved version but there's another one that's all together straight as a ruler. When the Emperor's Blade was mentioned in the Japanese raw, it's written as 大太刀 (Odachi), the long curved kind of katana.

On another note, 太刀 can also be read as Tachi so 大太刀 may also be read as O-Tachi. Got to love Japanese language sometimes... whereas in this case it's more akin to the kind of katana referred to as 大刀 or 直刀.

As you can guess, this actually refers to the straight kind of katana and actually bear some semblance to the Chinese straight sword you mentioned. I guess the one Cocytus has is actually the straight kind whereas the 大太刀 Ainz used in Shalltear's execution is shown to be the curved kind if the anime is any indication.