Lulu
Lulu, the Black Mage
One of the main characters of Final Fantasy X, Lulu is a black mage serving as guardian to Yuna. She is 22 years old during the events of the game, and grew up on Besaid Island with Yuna, Wakka, and Chappu (Wakka's younger brother).
Lulu is a bit short of temper and generally has a very stern and scathing personality - she doesn't believe in babying people. She does care deeply for those who are close to her, though. She is also a very intelligent person. She, like most of the people of Spira, follows the religion of Yevon, but unlike most has no problem in questioning things objectively.
Yuna's pilgrimage is not the first time that Lulu has served as the guardian to a summoner. Her second pilgrimage, with Father Zuke, ended early when they reached the Calm Lands and he decided to not continue on. Her first time acting as guardian came to an end when Lady Ginnem, her summoner, was killed in the Cavern of the Stolen Fayth. This continued to bother Lulu, until Yuna's party decided to take a detour to the Cavern; there they meet Ginnem as an unsent. After Yojimbo - Ginnem's aeon - is defeated, Yuna sends the dead summoner to the Farplane, where she can rest in peace, and Lulu's mind can be eased.
Lulu had been in love with Wakka's brother, Chappu; however nothing came of this because he was killed fighting Sin. This event greatly affected her for a long time, causing her to be more withdrawn and caustic towards other people. She and Wakka eventually fall in love, though, and they marry not long after the end of FFX. They later have a son named Vidina.
Lulu is a powerful black mage, using magic to devastating effect against enemies. However, her physical attacks are very weak. Most of her spells are element-based; her most powerful is Ultima, a non-elemental spell that deals out heavy damage to all enemies.
Lulu's weapons take the form of small dolls that she holds; they can run up to and hit an enemy. Some of them will inflict various status effects on the fiends. Her Celestial Weapon is the Onion Knight. Her armor consists of colorful bangles.
Lulu's Overdrive is Fury, in which she can cast any spell multiple times for free.