Whoa, whoa, whoa...hold on a minute...
when you talk to Dario with Riddel, Karsh has a flashback again. Now, it was said that the evil Masamune brought out the deepest envy and hatred of the one who possesses it. When Karsh had his flashback, Dario was the one that took the sword, but Karsh asked himself later why HE was possessed by the sword. also, in the second flashback before you fight dario, Lynx picked up the Masamune. Why didn't he go crazy? and howd the sword end up in the Sea of Eden?