Lulu

Lulu is a playable character in Final Fantasy X who also appears in Final Fantasy X-2 as a non-player character. She is one of Yuna's guardians.

Since Lulu grew up with Yuna in Besaid, she and Wakka view her as a younger sister. Lulu was Wakka's brother Chappu's girlfriend, and still grieves over his death. Her stoic and self-possessed nature makes her seem insensitive, but conceals a gentleness underneath. She is instrumental in supporting Tidus to adjust to the world of Spira, although she does not initially believe his claim of hailing from Zanarkand.

Lulu specializes in the art of Blk Magic, with her Sphere Grid giving her access to many offensive spells, and her Overdrive, Fury, allows her to cast many Blk Magic spells rapidly. She commands various dolls to attack and help her cast spells, and equips bangles as defensive gear. Her Celestial Weapon, Onion Knight, reduces the cost of casting a spell to 2 MP, and amplifies the damage her spells deal.

(Source: Final Fantasy Wikia)