As a member of the Army of the Queen, Thaegwyl was posted at the edges of the Summer Country during the Age of Terror. There, he met a changeling coming through with a pair of mortals, and that changeling turned his life into something he never believed it could be.

As a faerie, he was vain, temperamental, and callous, but upon meeting and learning from this changeling, things began to change. He found religion, raised himself in the ranks of the army, and began to seek ways to connect to the mortal world. He fought in the wars against the unseelie, doing his level best to stave off the forces of Terror and find a way to win the heart of the changeling woman, Jumana.

When the Runners returned and began becoming Champions, in his newfound and naive faith, Thaegwyl decided to prove himself--he took the Mountain of Trials while on a routine patrol through the lower boundaries of his reality. Upon the Mountain, he faced not just the hardships of the Catacombic reality, but also a lot of his own flaws--arrogance, naivete, brashness, and so on, finding he had to leave them behind to survive. At the Eye of Chaos, he humbled himself. At the Test of Temptation, he had to leave behind his naivete, and at the Test of Combat, he had to be cautious, strategic, and patient. In the end, he slew the Beast of the Mountain's incarnation and stepped out a Champion.

His greatest feats since then have been to alter the faerie races through the Dreamer God's Dreams, changing their weakness to iron and steel to their only weakness and to rule the Epoch of the Indigo Mantle and defeat the second Master of the Wild Hunt.

Now he and his wife, Jumana, are working for the Faerie Queen to understand the slow-coming elven extinction.