Uxie

Uxie (Japanese: ユクシー Yukushii) is a -type Pokémon introduced in Generation IV. It is part of the Legendary Trio, along with Mesprit and Azelf, found in the Sinnoh region.

Physiology
Uxie is a greyish-blue, fairy-like Pokémon. Uxie has a two long, leaf-like tails encrusted the red gems. It has yellow face and its eyes are closed. Uxie's eyes are closed because it is said to wipe the memories of all who gaze upon it. Uxie has a yellow brain-like helmet with another red gem onto its forehead. Normally, Uxie is a genderless Pokémon but it is referred to as male in the Pokémon Mystery Dungeon series.

Evolution
Uxie does not evolve.

Pokémon Platinum
Along with Mesprit and Azelf, Uxie will help guide the player through the Distortion World to capture Giratina. After the game is completed, the player can head back to Lake Acuity and capture Uxie.

Explorers of Time/Darkness/Sky
In Pokémon Mystery Dungeon Darkness/Time/Sky, it was found in Fogbound Lake. Just like its species, it was so knowledgeable and loyal of all Pokémon. It is shown that he can create illusions, being credited with creating all knowledge in the Pokémon universe. Uxie was first encountered after the hero and partner defeats Groudon (which is made by an illusion), and it appears, allowing them to enter Fogbound Lake.The Guild members appeared and got shocked after they saw an illusion Groudon generated by Uxie. As they start watching the giant fountain-like light alongside with Volbeat and Illumise, Uxie feels happy of everyone's visit and Chatot tells everyone to go back to the guild after a big expedition. Uxie lets them go, warning them to keep this place a secret from the outside. Some time later, Grovyle defeats Uxie and steals the Time Gear from Fogbound Lake. Uxie was mentioned when the player defeats Mesprit, informing the player that Uxie is aware that its Time Gear was stolen because Uxie used telepathy to tell her what happened.

Pokémon Black 2/White 2
After the player had defeated the Champion, they can go to the areas past the Skyarrow Bridge. In Nacrene City, the player can head to the Nacrene Museum, and once they are right in front of the entrance, a text box will read that a mysterious presence can be felt, and if they would like to search around. If they choose yes, Uxie will appear.