a new dps class that uses a katana as primary weapon

[Malzian]

Ninjas use Wakazashi, not katanas. And if the SAM were to use anything, I would like to see then use an Odachi.

I was going to make this comment myself before I saw this post. There is no such thing as a 'Great Katana', they just don't exist and if you really want a long Japanese sword a Nodachi (almost interchangeable with Odachi, but there's a slight difference in the meaning where Nodachi fits the concept better) would be what you are looking for.