User blog comment:Rayn Larusse/bad redwallers/@comment-1421927-20100613171354

He was probably experiencing bloodwrath or something near it. And, as Holly said, he was part of the horde, which probably meant he had slaughtered many, many innocent creatures. Cluny was using Killconey as a human-shield, so it wasn't Matthias fault, really, it was Cluny's, because Matthias could have been swinging his sword for a death blow to Cluny, when Killconey got in the way, and Matthias couldn't to the sword, so, woosh, Killconey dies.