The most anticipated character after Oldman, Rikkus finally here! If you have no idea why all the hype around her, tag along and Ill show you. Rikkus most relevant stat is actually LB Crystals per Turn, aside from the standard HP/MP for sustainability and SPR for taking hits, so well skip the stats.
Equipment selection is okay for a support, being able to wield Daggers, Knuckles and Throwing Weapons and wear Clothes, Light Armour, Hats and Shields. Knuckles are specially relevant for Overrides amazing +100% LB Fill Rate.
Skillset is pretty varied: Lucky Girl (20% Chance Dodge Physical Attack & Decrease Target Chance by 30%) provides some innate dodge chance and reduced target, Al Bhed Potion (AoE 1000 HP Recovery & AoE Cure Poison, Silence, Petrify) is a mini Curaja+Esunaga on an ability and Mega Phoenix (AoE Revive with 100% HP) is a crazy expensive (70 MP), but still very good, on-demand AoE Full-Raise.
Rikku also has access to Mix (Grant Sunburst, Hazardous Shell and Ultra NulAll for 3 Turns). Sunburst (AoE 19998 Damage Attack) is a fixed damage finisher à la Setzer, Hazardous Shell (180% AoE 1 Hit Physical Attack & 2 Random Status Effects (30% All Ailments, 100% Petrify)) is your ailment inducer and Utra NullAll (AoE 3 Turn +40% All Elements Resist & AoE 3 Turn 30% Damage Reduction) is Elemental Resists bundled with an excellent damage mitigator.
Even though it might be niche, you can also use Rikku as a chainer, as she has access to Winter Storm, Tidal Wave, Burning Soul and Lightning Bolt (230% ST 9 Hit Ice/Water/Fire/Thunder Physical Attack, Respectively). Even though she provides 4 different elemental chains, they all have different frame data and dont really chain well with anyone besides herself.
Finally, her LB kit is comprised of Overdrive Boost (LB Fill Rate +100%) and the LB itself as a fantastic (AoE 3 Turn +50% -> 74% DEF/SPR & AoE 3 Turn Auto-Revive with 80% HP). So not only does it have Cecil levels of defensive stat buffing, but it provides the unprecedented AoE Auto-Revive. This little guy makes so many freaking fights that much easier its not even fair, so stack as many +LB things you can on Rikku and youre pretty much set.
Japanese Altema Rating: 98/100 (After Enhancements)
Global Trust Mastery Rating: Backpack - +3 DEF, Grant Chaos Grenade, Cure All and Eccentric - Accessory - 9.4/10
This fantastic mastery provides the following skills: Chaos Grenade (180% AoE 1 Hit Physical Attack & Inflict 1 Random Status Effects, (30% All/100% Petrify) & 3 Turn -30% ATK/DEF/MAG/SPR Debuff) as an AoE Full-Break and Ailment inducer, Cure All (AoE Cure All Ailments) as literally Esunaga and Eccentric (5 Turn AoE 200% LB Fill Rate) as an excellent LB booster.
This is great not only on Rikku, but on pretty much any support character. Giving your party a 5 turn +200% LB Fill Rate is no joke and having a backup Esunaga is always a good idea. The Full-Break is pretty outdated, but its still an option if need be.
Japanese TM Rating (altema.jp): S Rank
Why would you want Rikku?: Really? She has:
Aoe 100% Revive
Curaja + Esunaga
Fixed Damage Finisher
AoE Ailment Inducer
AoE Elemental Resistance Buff
AoE 30% Damage Mitigation
9 Hit Chainers for 4 different elements
50~75% Defensive Stat Buff on her LB
3 Turn AoE Auto-Revive on her LB
Im just gonna leave it at that. Rikku puts so many support units on the ground its not even fair.
What about the future? You probably already know of the many fights Rikku makes bearable or even doable, so Ill just give you a few reasons why you would bring another support unit instead. The first and major reason is that, even though she has a great 30% Damage Mitigation skill, its behind a 1 turn setup, so its not on-demand like Crowe or 9S. Other reasons are minor and tied to specific fights, but Rikku has no access to good breaks or heals or any sort of mana-battery, so you might need that more than what she can offer.
She also received her enhancements in JPN and while they werent game breaking (I mean, could you even break her further?), they offer some nice additions. The main one is an upgrade to Mix, adding a ST 100% Heal and extending the availability of the granted skills to 4 turns. The other enhancements are minor: she gets some ATK bonus when wielding a Knuckle and excellent +30% MP when wielding a shield. Finally, her Tidal Wave gets upgraded to 280% modifiers and 12 Hits (and 12 frames instead of 9) for some reason.