Uxie is a small, gray, fairy-like Pokémon with two gray tails that are each encrusted with a red gem. Uxie has a partially yellow face with another red gem encrusted into its forehead. Its head faintly resembles that of a helmet or a human brain.
Uxie always has its eyes closed, as it can wipe out the memory of those who see its eyes.
Uxie is both feared and respected for its ability erase the memories of evil people. Uxie's spirit can leave its body without dying, and return at will. It created all knowledge in the Pokémon universe. Notably, when Uxie first emerged, humans gained the knowledge needed to solve problems and improved their quality of life. In Pokémon Mystery Dungeon: Explorers of Time and Explorers of Darkness, it is shown that Uxie can create an illusion. It was also shown in The Needs of the Three! and The Battle Finale of Legend! to teleport itself, as well as other Pokémon and humans. Though it is very shy, Uxie will attack with force if it or the other lake guardians, Mesprit and Azelf, are threatened. Uxie has been referred to as "The Being of Knowledge." Uxie and the other lake guardians have the power to calm Dialga/Palkia should the deity be enraged.
In the Diamond & Pearl chapter, Uxie was to be captured as part of Team Galactic's plans. Commander Jupiter led the operation to capture Uxie, and overcame resistance from Maylene, Candice and Platinum in order to do so. Uxie connected with Platinum the most, as Platinum had great wisdom; she had also been to Lake Acuity before and saw Uxie, though she did not remember the event. It first appeared in Tackling Tangrowth.
Pokémon Diamond and Pearl Adventure!
Along with Mesprit and Azelf, Uxie was captured by Team Galactic to create the Red Chain so that they can control the Legendary Dialga. It was eventually freed and helped stop Dialga by breaking the Red Chain. It first appeared in A Novel Test!!.
A Knowledge Pokémon. It's said that Uxie's emergence gave humans the wisdom to improve their lives. This Pokémon possesses the ability to erase the memory of those who see its eyes. Uxie uses status-altering moves in battle--its frequent use of Yawn is very effective in putting foes to sleep. Uxie makes its home in Lake Acuity in the Sinnoh region.
Uxie seems to be based on a pixie or a fairy and the color yellow. Uxie and the rest of the trio could possibly have originated from the Imperial Regalia of Japan, which are also called the Three Sacred Treasures. Uxie would be the Yata no Kagami, which embodies wisdom and honesty.
Uxie and Yuxie may be a combination of U of the acronym UMA (Unidentified Mysterious Animal, wasei-eigo for cryptid) and pixie. It may also involve the pronoun you.