Vivi's battle performance during the game:

General information:

As a Black Mage, Vivi is pretty weak with physical attacks (although he's too cute when you make him bounce to the enemy and give a blow with his cane ^^). Vivi's main strength resides of course in the use of Black Magic, or attack-oriented spells. Most of these spells are elemental and consequently, some of them may be useful to defeat enemies, while others aren't efficient or even worse, may heal the enemy! Since Vivi hasn't a good physical strength, one of the most important things to do is to put him in the back row, since his magic attacks deal the same damage no matter which position he's in (front or back), and also to benefit from the damage reduction every time he gets a physical hit from an enemy.

In the beginning...

When you get control of Vivi for the first time, his Mage Cane makes him learn a basic Black Magic spell (which will be used several times outside battle and even in an FMV): Fire. The Silk Shirt, found a bit later in the game (I think you obtain it if you score 80% to 99% in the sword performance with Zidane and Blank), makes him learn Thunder. So you'll easily guess what to do with those two...

Your first fight with our lil' Black Mage is on the stage of the Prima Vista: Zidane, Garnet, Vivi and Marcus VS Steiner and two Pluto Knights. Be sure that Vivi is in the back row to prevent him from getting too much damage.

More spells: Vivi gets to learn new spells later in the game as you acquire equipments in shops, in chests or from monster bosses. Most of the spells are contained in the Canes. One thing I should add: since Vivi's physical strength is almost never tested throughout the entire game, keep the Cane in his hands until he learns the spells from it before giving him another, except if you have a Cane containing an adequate spell for an expected "Boss Fight"...

Focus: each time Vivi "Focuses", he closes his eyes and concentrates, making magic power increasing until the end of the battle. This command gets handy if you use it 4 or 5 times in the beginning of the fight. You may cast Haste on Vivi or junction Auto-Haste to him in order to accelerate the process. The advantage in using this command is that the magic boost isn't lost when Vivi gets KOed! However, this command gets obsolete when Vivi obtains Reflect X2, explained later...

Steiner's Sword Magic: Vivi and Steiner need to be both standing to perform this attack. Not all the Black Magics learned from Vivi are able to be used as Sword Magics. Notice it well: Vivi faces Steiner and casts the spell... but Steiner spends MPs!
Unlike Vivi's spells, this technique is always employed on a single target. A remarkable advantage: the Doomsday sword will only affect one opponent instead of hitting all the battlefield! Using this technique against elementary enemies pays off, until Steiner learns "Shock!"... and gets a way to deal 9999 per blow.

Trance Status: when Vivi enters Trance mode, he's able to cast two spells in a row, no matter what spells they are, no matter what the target is, providing that you have a sufficient amount of MP to afford it. Notice that, since you make him do two actions, his Trance gauge decreases twice if you use the Black Magic command. Anyway, his Trance mode lasts at least three rounds if he keeps on acting this way. Vivi automatically enters Trance mode in the beginning of the battle against Black Waltz 3. See that his clothing gets a bit different, and his folded pointed hat straightens up when he gets in Trance.
The more Vivi levels up, the longer he's able to remain in Trance.

Where / when will you have to travel and / or fight with him?

In the first two CDs, you can't change your team lineup, so you have to play with Vivi whenever he shows up. You get to control him (on his own) in Alexandria in the beginning of the first CD, and also in the beginning of the third CD.

Once you reach Treno in the third CD, during the Card Tournament, you can choose to learn more about Vivi's past during an ATE. You will have to search for him as Zidane in Quan's lair.

You will only be able to switch between members once you get into the Blue Narciss. However, since many enemies have an elemental weakness, it may be good to keep him.

I strongly advise you NOT to take Vivi in Oeilvert, he will not be able to use his magic since Oeilvert forbids the use of all magic spells! Keep the Black Mage for later in the Desert Palace, he will be extremely handy against the resident Boss...

Vivi automatically joins your team in Esto Gaza, but will not be able to fight the "local boss", Meltigemini.

Vivi doesn't fight in the sequence in Terra when Zidane turns mad, Zidane leaves him behind with Eiko.

Finally, Vivi happens to be very strong against the bosses in the 4th CD, all of them are elemental (except Trance Kuja). This said, I still keep him for Necron and attempt to use the ReflectX2+AutoReflect+Flare technique (explained later)

Spell list:
- Fire, Fira, Firaga: level 1,2,3 fire-elemental spells to one or multiple targets.
- Sleep: inflicts the Sleep status ailment to a single target.
- Blizzard, Blizzara, Blizzaga: ice-elemental spells. One or multiple targets.
- Slow: inflicts this status ailment to a single target.
- Thunder, Thundara, Thundaga: lightning-elemental spells. One or multiple targets.
- Stop: freezes a single target's movements. Considered as a fatal status if your party is hit by this spell.
- Poison, Bio: level 1 and 2 poison attacks. May cause the Poison status ailment.
- Osmose: sucks MPs from the enemy, unless you want to use Ethers or Elixirs.
- Drain: sucks HPs from the enemy. Never use sucking spells to undead people!
- Demi: launches a gravity attack to reduce to half the target's HP. Doesn't work upon all enemies.
- Comet: non-elemental attack on one target.
- Death: the target is instantly KO. Doesn't work every time, and is unefficient against bosses.
- Stone: petrifies the target. Same remarks for the Death spell.
- Water: middle-level water attack on a single target. Though this spell has no gradations (as Fire and the like), Kraken from Memoria uses Waterga to regenerate. Lulu from FF10 will get this spell coming with -ra and -ga though...
- Meteor: non-elemental attack striking all enemies, but sometimes misses. Focus before launching it.
- Flare: the famous defense-breaking spell. Targets one enemy, yet can be reflected or weakened by a Shell spell.
- Doomsday: extremely high-damage dark-elemental spell strikes enemies AND allies! Ozma's favorite spell... this spell may be harmless to all allies carrying armors and relics nullifying (or even absorbing) dark elemental spells, such as the 2 Pumice Pieces. On the other hand, if you really want to use dark elements, either use Steiner's Sword Magic or Ark. This is the last spell Vivi will come across, and the cane handling it is obtained from a chest, before the entrance to the Crystal World.

Support abilities you should use to optimize Vivi's magic:
- No Reflect: this support ability simply ignores the Reflect status of any spell's target.
- Half MP: a very good ability. All spell costs for Vivi are divided by 2!
- No Element: all elemental spells are considered non-elemental. Becomes obsolete once Vivi gets to learn Flare.
- MP+20%: as the name says, it increases Vivi's max MPs by 20%. Not as interesting than Half MP though.
- Auto-Reflect: Vivi starts the battle with a permanent Reflect status! Works in conjunction with...
- Reflect X2: now this is why Focus becomes obsolete near the end of the game! This ability doubles the amount of damage caused by an already Reflected spell. Use any of your damaging black magic spells except Doomsday upon a Reflected ally for a double damage! I recommend you not to use Dagger's Reflect nor Eiko's Carbuncle for this, the Reflect status provided by those two spells isn't permanent, and may cause some unwanted things to happen! Other thing you have to check if you want to rely upon Reflect X2: turn off "No Reflect" or you'll be quite surprised...

Just try to have him in Trance mode, cast Flare twice on a Reflected party member with ReflectX2 activated!