Self-Loathing and Greed
Eisen swung his sword to the side to get rid of the blood that had been stuck on it, watching as the body of the man with the perfect memory was repairing itself. And the moment that he was able to stand up again, Eisen slashed downward with his blade once more. Due to the sheer weight of the blade, combined with the old man's strength and of course the support of the sword's ego itself, the old man was able to cut through him with ease.
The old man continued to do this over and over again, hacking his target into small pieces. Everyone was staring at him as he was doing so, but none were brave enough to help Eisen's victim. There were a couple people here that became envious of Eisen's strength and his blade now, though. And somehow... it made him feel pretty good.