http://www.fanfiction.net/s/5233033/1/TheWarriorsWord

Matchmaker!Stu, Omniscient!Stu, Warrior!Stu, and Magic!Stu all rolled into one mouse known as William the Warrior. He can shape-change, turn beasts into dust, conjure anything he wants, and kill enemies with one swing of his booteeful six-pommel-stoned sword. He also has white, strength-enhancing armor that enables him to catch large boulders (catapult fodder, mind you) and hurl them back. And did I mention he plays matchmaker for Matthias and Cornflower?

Geez, why doesn't he just kill Cluny and be done with it? It's quite clear to me that this is completely within his abilities.

This makes me wonder if the writer didn't just look up Mary Sue on Wikipedia and make a character out of it.