Final Fantasy X/Lulu

Background
Lulu is principally a guardian of summoners, and although having grown up on Besaid island has accompanied 2 summoners on their pilgrimages before the journey with Yuna. Her first summoner (Lady Ginnem) died on the pilgrimage, which still haunts Lulu to this day, whereas the second (Father Zuke) mutually agreed with Lulu to give up his pilgrimage when they reached the Calm Lands. Lulu was romantically involved with Wakka's younger brother Chappu before he was killed in a battle with Sin after joining the Crusaders. Again this clearly still affects Lulu, although the sexual tension between her and Wakka is not only clear throughout the game but explicitly mentioned on various occasions (often by Tidus).

Basic Fighting Style
Lulu will mainly be deployed as a black mage throughout the game, as she gains a variety of offensive black magic spells on her trip along the sphere grid. Lulu will most likely have the lowest HP and among the highest MP of the characters, and has a good magic stat that allows her spells to do a devastating amount of damage when elemental weaknesses are properly exploited. Lulu truly excels in magic defence, easily having the highest among all the characters, which somewhat makes up for her low physical defence. Lulu's accuracy and strength are both very low, so don't expect to be slaughtering flying enemies with Lulu's collection of dolls. Lulu has average agility, but very good evasion and her spells can hit enemies that are out of range to everything else but Wakka's deadly ball.

If you take on the monster arena or dark aeons it is possible that you may want to use Lulu, as she has a usable bonus on her celestial weapon. However Yuna has a much better magic stat to build on (as well a summoning abilities), and Lulu's overdrive leaves a lot to be desired compared to the much more deadly overdrives of Tidus and Wakka. So although Lulu could be used for these purposes, the chances are you probably won't have room for her in your offensive force.

Notable Skills
The skills that Lulu gains on her initial route on the sphere grid are detailed below:

Fire - Basic fire spell that inflicts a small amount of fire damage on one enemy.

Thunder - Basic thunder spell that inflicts a small amount of lightning damage on one enemy.

Water - Basic water spell that inflicts a small amount of water damage on one enemy.

Blizzard - Basic blizzard spell that inflicts a small amount of ice damage on one enemy.

Focus - Increases the magic and magic defence of all allies, the effect can be stacked up to 5 times.

Fira - Mid-level fire spell that inflicts a medium amount of fire damage on one enemy.

Thundara - Mid-level thunder spell that inflicts a medium amount of lightning damage on one enemy.

Watera - Mid-level water spell that inflicts a medium amount of water damage on one enemy.

Blizzara - Mid-level blizzard spell that inflicts a medium amount of ice damage on one enemy.

Reflex - Raises the evasion of all allies, the effect can be stacked up to 5 times.

Bio - Causes poison on one enemy.

Demi - Reduces the HP of all enemies by one quarter. It won't break the damage limit unless you have a weapon that can do so, so for example if the target has 60,000 HP it'll do 9999 rather than 15,000.

Death - Can instantly KO the target.

Waterga - Most powerful water spell that inflicts a large amount of water damage.

Thundaga - Most powerful thunder spell that inflicts a large amount of lightning damage.

Firaga - Most powerful fire spell that inflicts a large amount of fire damage.

Blizzaga - Most powerful blizzard spell that inflicts a large amount of ice damage.

Flare - Inflicts a very large amount of non-elemental damage on one enemy.

Ultima - Inflicts an extremely large amount of non-elemental damage on all enemies, and penetrates shell and reflect. (Requires 3 lvl. 4 locks to be opened at the start of Lulu's grid).

Doublecast - Allows 2 black magic spells to be cast in one turn. (Requires 1 lvl. 3 and 1 lvl. 4 lock to be opened towards the end of Lulu's grid).

Overdrive
Lulu's overdrive is called Fury, and when activated you must choose one black magic ability that will be cast many times. Any black magic spell can be used, and the process does not require any MP. You then have 4 seconds to rotate psx: Neutral Lstick as many times as possible, with the amount of spells that will be cast building up as you rotate it. More powerful spells require more rotations to add an extra spell to the counter, and a higher magic stat reduces the number of rotations required to add an extra spell to the counter. The spells are cast randomly against the enemies at half normal casting strength. An enemy can be hit multiple times (although it will not be hit any more if it dies, so your spells aren't wasted), and the total damage of all the spells that hit it (rather than each spell individually) determines an overkill.

Note: Since Bio doesn't inflict damage, Bio Fury uses spells that have roughly a half as likely chance of inflicting poison on the targets (the actual chance is then determined by status effect resistances, for example a monster with no resistance to poison will succumb to a spell from Bio Fury half the time, and one with a 50% resistance to it will succumb 25% of the time). Demi Fury spells hit for 1/8 of the target's health rather than 1/4, and some monsters that are affected by Demi (bosses in particular are often immune to gravity) may be immune to Demi Fury. Death Fury works in a similar way to Bio Fury.

Celestial Weapon
Lulu's Celestial weapon is the Onion Knight, and is powered up by the Venus Crest, then the Venus Sigil. Obtaining the weapon will require the Celestial Mirror, as will powering it up.

Obtaining the Weapon
The chest is found at Baaj Temple after fighting the boss. It is located underwater, opposite the door to the temple, and can only be seen when the perspective changes after you open the chest. Therefore you should float around the general area and mash the psx: X button until you find the chest (which will only work if you have the Celestial mirror).

Venus Crest
Return to the farplane after you have completed your tasks in Guadosalam, view the extra cut-scenes involving Lulu and Wakka, and then you can open the chest with the Venus Crest in it.

Venus Sigil
You must dodge lightning at the Thunder Plains 200 consecutive times. This means as soon as you see a flash of light on the screen you must press the psx: X button to dodge the lightning, and do this 200 times in a row without changing screens or saving. If you just mash the psx: X button you will only get struck by lightning for cheating. No-encounters is almost necessary to complete this task, which can be customised with 30 purifying salts (dropped by fallen monks in the Zanarkand Dome), or a weapon with the ability is often dropped by the boss at Baaj Temple. Although this task takes a lot of patience, it isn't that hard, and you will easily complete it with perseverance. So when you think you have dodged 200 bolts, dodge a few more to be on the safe side and return to the travel agency, outside which you will be able to open the chest containing the Venus Sigil if you have successfully completed the task (otherwise it may just contain a standard item).

Final Outcome
Power up the Onion Knight with both Venus Crest and Sigil and the outcome will be
 * Weapon Effects:
 * Break Damage Limit
 * Triple Overdrive
 * Magic Booster
 * One MP cost
 * Does more damage when Yuna has a higher percentage of her MP remaining
 * Allows Shiva to break damage limit