How Do I Defeat Yomi

I can tell you now there isn't a clear-cut winner for each role. But there are definitely monsters that excel more than others in their roles. Here's a list with some great monsters and why (this is partially taken from the official guide and partially my own experience):

Commandos:

• Chichu: Has very high strength stats and the valuable armor breaker and various "feeder" abilities.

• Dragoon: According to the guide the most cost effective monster (easy to max out and has some great abilities like Feral Speed 2, ATB charge 2, and Armor Breaker).

• Red/Golden Chocobo: Both have excellent potential but it would be wise to infuse them with pack mentality.

• Tonberry / Don Tonberry: They are amazing all-around Commandos but Tonberry is probably a bit better seeing as Don Tonberry continually has poison on him.

• Twilight Odin: Probably the most lopsided in stat growth and incredibly expensive to max out. However, once you do max him out his stats are almost peerless and he is one of the few monsters capable of a full ATB gauge of six elements.

Ravagers:

• Buccaboo: Great early peaker that is recruitable early game and the cheapest source of Gilfinder 2.

• Apotamkin: It's an early peaker with fairly high stats and has access to all elemental spells of the first two tiers and all physical strikes as well. Although the monster only has a 2% chance of being recruited.

• Blue Chocobo: Is the best choice for an ultimate all-around Ravager. Although you should try to infuse elemental spells that it does not learn naturally and infuse it with useful passives.

Sentinels:

• Pulse Knight: As an early game Sentinel it's the best and easy to max out. It also boasts the +25% HP passive which you can later infuse into another Sentinel.

• Bunkerbeast: Is a good choice for a long-term investment. It learns Challenge early on and boasts a massive HP pool (8000-ish). The only downside is that he doesn't learn Mediguard but you can infuse that ability.

• Silver Chocobo: Offers final stats similar to Bunkerbeast but at a lower cost. It's also the best chocobo to race with in Serendipity.

Saboteurs:

• Black Chocobo, Chelicerata, Necrosis, or Dendrobium. The first three have the improved debuffing passive. Dendrobium is a cheaper alternative and in all other ways just as viable.

Synergists:

• Amanojake: Notable only for infusion fodder learning all three of the en- spells which have high damage boosting potential.

• Gahongas: Earliest monster you will encounter that has both Bravery and Faith although you might be struggling to maintain its development.

• Yakshini: One of the better choices as your main offensive Synergist for a large portion of the game. It's fairly cheap to develop, relatively durable, and built for offense.

• Purple Chocobo: Best choice for a level 99 Synergist but given the advantages of narrow specialization you may wish to keep other Synergists as well.

Medics:

• Caterchipillar: Only natural bearer of the passive skill Resist Elements +30% and therefore makes for good infusion fodder.

• Flanitor: Probably the most accessible source of both Cura and Esunada and learns Improved Cure 2.

• Green Chocobo: Best candidate for a level 99 Medic: just be sure you infuse Esuna and Esunada from a Flanitor.

There are a number of strategies to use for them. I recommend maxing out all of your jobs and your three monsters having more then 2000 HP.

Monsters

• Vodianoi level 17 COM
• Gremlin level 40 RAV
• Green Chocobo level 27 MED

Accessories

Noel was 3 Power Wristbands and for Serah I used Hypnocrown, Durable and Delicate Magician's Mark.

Paradigms

COM COM COM Cerberus
RAV COM RAV* Relentless Assault
RAV SAB RAV* Smart Bomb
RAV COM MED* Diversity
SAB SAB MED* Safe Subversion
MED MED MED Salvation
The ones I've starred are the more critical ones I used. The all COM paradigm is nice to have if you cannot finish them before the stagger bar empties.

The fight can be broken up into three parts one is when, Lightning is alone and you just need to get her hp down to about 3/4 which isnt very hard, and the second phase is when Amodar joins the battle (COM COM) the two of them work more on party damage with Amodars grenade or him simply attacking all party members if close enough. Lighting dealing party damage with Ruinga. After about 2 mins in they change to either SAB SYN, SAB MED or COM RAV. When Amodar is a SAB he inflicts just about anything on the party member he attacks so I recommend going after him first, plus Lightning is easier to take out alone without his debuffs.

At the start of phase two I recommend either RAV SAB RAV if you think you're good enough, or SAB SAB MED to keep more HP. (Note my chocobo did die often so have many phoenix downs and potions, possibly if you desire remedys) you can only inflict Deprotect and Deshell on Lightning and Imperil and Poison on Amodar however you really only need Imperil. Once you have that on Amodar, switch to either RAV COM RAV or RAV COM MED and stagger him. He does have a lot of HP but if you either get his HP to 999.99 or about 1/3 of the way empty change to COM COM COM and you should be okay. This also works on Lightning, however Amodar like to switch to SAB and cast a lot of debuffs on your party.

Now comes the third phase, either Lightning or Amodar are alone and they cast a few buffs on themselves which cannot be dispelled. I recommend switching to RAV SAB RAV and repeating the above on them, and then switch to RAV COM RAV and try to stagger them. Before you can, they usually get off about 2 Feral Links but Lightnings is weaker and wont instantly kill your party members (except Noel). With this party I recommend having atleast 20 Phoenix Downs to revive your monster and Sarah or Noel if they die.