Mirth is the current incarnation in a long line of World Magi. In one former life he was Merlin, the magician and adviser to King Arthur Pendragon. When we first meet Mirth he is in his full power, having been aware of who he is since an early age. His past in this lifetime is a complete mystery. We get to know little about him other than the fact that at some point he lost his legs, and now uses magical leg wrapping as replacements. Later, during The Hero Defined story arc, we learn that Mirth is living his life backwards, and that the Wally Ut character is his teen-aged self.
Mirth was created by writer/artist Matt Wagner for his story Mage: The Hero Discovered. So far Mirth's back story has mostly remained a mystery owing to the fact that the main protagonist of this tale is Kevin Matchstick, the Hero.
In the beginning, Mirth is an enigmatic cypher. He has one job to accomplish, and he does it well. It's his task to awaken the powers dormant within Kevin Matchstick, and to set him on the path to becoming a hero. Mirth answers questions sparingly, and reveals information slowly which frustrates Kevin, but allows him time to process the massive life changes that are happening to him. We get the impression that Mirth has done this many times before. Mirth, as his name implies, tends to love life, make jokes, and have fun, although by no means is he shallow. Instead he just tries to enjoy things while he has the chance, and when necessary can speak the truth bluntly. He has a marked weakness for women. In the Hero Defined story arc, we are introduced to Wally Ut, a teen-aged version of Mirth. We learn that Mirth is living his life backwards through time, and that Wally is young, not as experienced with his powers, and is often confused by his constant state of seeing the future.
Major Story Arcs
As Mirth, the World Mage's major story arc is The Hero Discovered where he sets the hero Kevin Matchstick on his path to leading the war against the darkness.
In The Hero Defined, as Wally Ut, it's his job to get the hero to recognize that he doesn't actually need Excalibur, nor is his mission succeeding if all he ever does is battle monsters. He must create light and not only destroy the dark. Unfortunately, Kevin is stubborn and arrogant. He ignores Wally's advice until nearly the end.
Even though Kevin's companions have mostly accepted Wally's status as a mage, Kevin still doubts. As with Doubting Thomas, he must see to believe, and so Wally transforms himself to Mirth. Mirth still has his white hair, but his empty leg wrappings have been replaced with a more life simulacrum of real legs. However, it turns out he is much shorter with real legs! He explains many things to Kevin, including the fact that Kevin is not only the incarnation of King Arthur, but also Gilgamesh, and possibly other heroes. He also reveals that Wally's hat once belonged to his past and future love, the Lady of the Lake, a.k.a. Edsel. Through this conversation with his long-missing friend, Kevin finally accepts Wally's identity, and Mirth transforms himself back into Wally Ut. Later, before Wally disappears, he says that the first mage was to inspire, the second to instruct...and can't remember what the third is supposed to do.
Powers and Abilities
As the World Mage, Mirth is the strongest user of magic on this plane of existence. He gains his power directly from the river of magic in the faerie realm. The magic runs naturally through him, and he can easily use it as he wishes. For Mirth, magic is pure green; for some other pure users of magic, it may appear to be other colors--for instance, Wally Ut uses purple magic. Evil users may also use the magic and pervert it to other, unnatural colors.
One of his main powers is the Sight, which allows him to see the future, specifically the futures that surround the people who will help Kevin Matchstick in his war against the darkness.
He has used his magic to teleport himself and others; to fly; to levitate other objects; to create a cushion and soften Edsel's fall; to erase memories; to erase computer and other records; to fix a set of broken prison bars; to create shields against attacks such as Redcap slings; to create a lasso; to animate his leg wrappings into acting like actual legs; to fix clothing; to walk in a kind of half real/half faerie dimension where normal people can't see him, but he can see other people; to transport himself and others directly into the realm of faerie magi;, and in extreme circumstances to attack, as he did against Stanis and the Umbra Sprite's Shade.
He also used his magic on the Bat (a.k.a. Excalibur). When Edsel first had it, it seemed like a normal baseball bat. He then said he enchanted it, giving it a slight stunning or shocking power, turning it green. However, he later admitted that in fact the Bat always had its power, and instead of enchanting it, he only revealed its power. In fact, he had to put great effort into keeping its power mostly hidden.
Many of his magical effects are done with little to no effort. Others, like when he went into the computer, or when he opened a portal to the Styx, take abundant effort, to the extent of the former actually turning his hair white.
The downside to Mirth's strong magical ability is that he is extremely easy to track by other magic users.