Joy

Joy was one of five Force Priestesses who had sustained their consciousness in the Force after death and dwelt inside the Wellspring of Life. She manifested as a being wearing a black robe and a cheerful mask, and acted in a manner befitting the emotional aspect she represented. When Jedi Grand Master Yoda came to the planet seeking immortality, she and the other priestesses set him a series of challenges to prove he was worthy of the "great gift". Yoda passed each of their tests, eventually traveling to the Sith homeworld Moraband where his final test—facing Sith Lords Darth Sidious and Count Dooku—was out of Joy and the other priestess control. Yoda succeeded, and the priestess informed him that the spirit of his old friend Qui-Gon Jinn would commune with him to teach him the ways of manifesting in the Force after death.

Text and facts from the “Joy” article on Wookieepedia, licensed under CC BY-SA 3.0. Modified for this site.