Vanille – Saboteur Crystarium

Character Vanille
Role Saboteur
Vanille is a very effective Saboteur with a variety of Abilities, though she is more concentrated on defense-lowering debuffs. She cannot inflict Slow, Curse, or Daze, and also lacks Fogga and Painga, but has single- and multi-target versions of every other Saboteur Ability. Beyond that, she has Death, a unique Ability that either just kills a target or deals a large amount of damage to them. Since very few non-boss enemies are actually immune to Death, you can get cheap, fast kills against a number of difficult foes (up to and including Adamantoises) with it.
Compare Vanille – Saboteur Crystarium to other Crystariums

Related

Vanille

Eidolon Hecatoncheir (Chapter 11)
Base HP 350
Maximum HP 21,050
Base Strength 23
Maximum Strength 1,400
Base Magic 35
Maximum Magic 1,700
Starting Weapon Binding Rod
Primary Roles Ravager, Saboteur, Medic
Accessory Crystal Saboteur 5
Accessory Crystal Medic 8
Accessory Crystal Ravager 10
ATB Level Crystal Medic 8
Chapter 1

Fang – Saboteur Crystarium

Character Fang
Role Saboteur
Though she lacks Vanille's Death Ability, Fang is perhaps the most effective Saboteur in the game, though her one glaring weakness, an inability to inflict Poison, is a problem against many of the toughest foes in the game. She also lacks the defense-lowering multi-target debuffs (Deprotega, Deshellga, Imperilga), but as a general rule you're only attacking one target at a time anyway, so this is not a big deal.

Hope – Saboteur Crystarium

Character Hope
Role Saboteur
Like Sazh, Hope is one of two Characters that can inflict every Status Ailment in the game. However, Hope exclusively gets multi-target versions of these debuffs (as well as the standard Dispel). This makes Hope an effective Saboteur against groups, but since his Abilities cost three times as many ATB segments, he's a liability when you're only looking to debuff a single target (which is usually the case). He can't even use two debuffs in a round without the Nue.

Lightning – Saboteur Crystarium

Character Lightning
Role Saboteur
As a secondary Role, it's not surprising that Lightning has a rather limited set of Saboteur Abilities. She lacks any way to inflict Slow, Curse, Daze, Fog, or Pain, and also lacks Dispel, which can be a problem against some foes. However, she does get both the single- and multiple-target forms of Deprotect, Deshell, Imperil, and Poison, making her quite good at lowering defenses of single enemies or entire groups.

Sazh – Saboteur Crystarium

Character Sazh
Role Saboteur
Sazh is a very effective Saboteur, gaining access to every single-target debuff in the game. In fact, he's one of only two Characters that can inflict every possible status ailment (the other being Hope). Because he relies on single-target debuffs, he's not very effective against groups, but then, Saboteurs are generally most important against singular, powerful enemies anyway.

Snow – Saboteur Crystarium

Character Snow
Role Saboteur
Snow's Saboteur is the complement to Lightning's, as he lacks the defense-lowering debuffs Deprotect, Deshell, Poison, and Imperil, but has full access to single- and multi-target versions of Slow, Curse, Daze, Fog, and Pain. Also like Lightning, he lacks access to Dispel. If you're fighting an enemy with powerful offensive abilities, Snow can be very effective, but he won't help you deal much damage against them.

Vanille – Commando Crystarium

Character Vanille
Role Commando
Vanille is the most limited Commando in the game (and has the silliest Weapon), lacking both Launch and Blitz. She does get Blindside and Faultsiphon, auto Abilities that are easy to take advantage of. However, her Role should generally be limited to that of a secondary Commando. She's more useful for the Augmented Attack effect than actual Commando Abilities.

Vanille – Medic Crystarium

Character Vanille
Role Medic
Vanille and Hope are the only Characters with access to every Medic Ability, and while Hope's magic stat is naturally higher, Vanille is plenty effective as a Medic as well. She and Hope are the only Characters who can use the amazing Curaja Ability, a vital healing spell in the endgame.

Vanille – Ravager Crystarium

Character Vanille
Role Ravager
Vanille is a good Ravager with a number of holes in her Ability list. Like Hope, she lacks any -strike Abilities, making her unable to damage enemies that are immune to Magic. She can still advance their chain bonus (and doesn't need to worry about strength!), but this can be a big problem against certain foes. She also lacks Aeroga, Thundaga, and Waterga, and doesn't get the Vigor Ability. None of this is crippling, but it does set Vanille firmly behind Hope as far as Ravagers go.

Vanille – Sentinel Crystarium

Character Vanille
Role Sentinel
Vanille as a Sentinel? Surely not! And truth be told, she's not very good at it. She has Mediguard at least, but not much else, including Challenge. She does have more HP than Lightning or Hope, but both of them are evasion Sentinels anyway. Basically, you don't want Vanille to be your main Sentinel. She's fine in the Tortoise (SEN/SEN/SEN) paradigm, but not much else.

Vanille – Synergist Crystarium

Character Vanille
Role Synergist
Along with Fang, Vanille is one of two Characters that has access to Bravera, Faithra, Protectra, and Shellra, high-powered Abilities that have a short duration to balance their extra effectiveness. Unlike Fang, Vanille has a decent number of standard Synergist Abilities as well, including Veil, Vigilance, and the Bar-spells. She is the only Character in the game that doesn't get Haste, however, so she's not very effective as your only Synergist.

Saboteur

Bonus Type Boosted Success Rates

Saboteur

Abbreviation SAB
Role Bonus Boosted Success Rates
Base Bonus (Self) None
Role Level I Bonus (Self) Success Bonus: +15%
Role Level II Bonus (Self) Success Bonus: +30%
Base Bonus (Allies) Success Bonus: +5%
Role Level II Bonus (Allies) Success Bonus: +8%
Role Accessory Impeder's Opal (Grants Success Bonus: +20% to self)