Quote Originally Posted by BG-57 View Post
Kotetsu is the strongest weapon you can get right at the beginning of the game. Roughly double in power than anything store-bought.

IIRC you can get the ninja sword Danjuro as a rare drop from the rare game Bombshell in Lhusu Mines extension. 12% chance at best.
The Yagyu Darkblade drops from the Bombshell, and the Danjuro drops from the Larva Eater in the Great Crystal. Both are too insanely stupid-hard to get.