A British Shaman and a traditional "dowser", whose parents were killed by Hao. Lyserg has dramatic interactions with all of the main characters at some point, and though he travels with them for a long time, he fights against Yoh's team more than once during the series.
Lyserg is an intelectualy genius but he is blinded by the prospet of revenge for his family's murder. He has a generally kind heart, although he becomes a bit of an anti-hero.
At first, Lyserg teams up with Yoh and his friends, but later joined the X-Laws, a group dedicated to destroying Hao. When Lyserg joins them, he is unsure about the ways the X-Laws try to eliminate Hao. Though Lyserg holds a deep hatred for Hao, his kindness and Yoh's own philosophies and personalities keep him from crossing the line.
In the anime (2001 version), Lyserg discards his first spirit as he gains control of Zeruel, an Archangel provided by Jeanne. In the manga, Lyserg never abandons Morphine, even when he is presented with the Archangel Zeruel.
His name is a drug reference to lysergic acid diethylamide. The name of his spirit, Morphine, is obviously a drug reference as well and thus was changed to Chloe and Morphea for the English version of both anime and manga. Moreover, his appearance is based on the stereotypical look of Sherlock Holmes, and Lyserg's dream is to be a famous detective in the future. He also loves reading detective and mystery stories.
