Yomi Yomi is a sidequest target in " Final Fantasy XIII - 2 " . One of the Undying , it can be encountered on the Archylte Steppe in stormy weather after accepting the quest to defeat it . " The Archylte Steppe becomes a very different place when thunder rolls across the heavens , for it heralds the coming of Yomi , one of the host of the Undying that is also known as the Wings of Death . " Datalog . " Why does it only appear with the lightning ? The answer lies in its former life . Yomi was once a great hero , driven to prove that he was the most powerful warrior of his age , but he was struck down by lightning on the steppe before he could complete his quest . " " Now he wanders the very same steppe where his life was so suddenly cut short . Amidst the crashing thunder and howling wind , no one hears his tormented screams . " Battle . Yomi could be considered a weaker version of Vercingetorix from " Final Fantasy XIII " since he has nearly 1 / 13 of Vercingetorix ' s total HP , and the strategy to deal with Yomi is no different . Like Vercingetorix , Yomi uses powerful Wind attacks and erects a barrier , called Impenetrable Aura , that makes it temporarily invulnerable , heals it from status ailments and partially restores its HP . Once Yomi ' s HP drops Yomi will get more aggressive and sprout more wings and will not use Impenetrable Aura as often . At this stage it will focus on using Wind Shear or Putrescence . Unlike Vercingetorix in " Final Fantasy XIII " , Yomi does not cast Doom ; only Gorgyra and Long Gui can cast it . Strategy . It is recommended to have Serah and Noel with at least 5000 HP , and a fully developed Crystarium helps greatly . The party can wear offensive accessories and it is good to equip Serah ' s Sagittarius and Noel ' s Mac an Luin since they allow one to queue six commands into the ATB bar . The most efficient monster to defeat Yomi is the Cactuar . It has a high attack and learns all of the passive abilities that work well against Yomi , namely Bravery Feeder , Deprotect Chaser , and Protect Feeder . The Cactuar ' s sky high attack damage can reach up to over 1 , 500 and its quick attack speed adds to its overall effectiveness . Since the Cactuar is small and jumpy , a good portion of Yomi ' s physical attacks will miss it . For a monster Synergist Yakshini or the Purple Chocobo are good choices . A Pulsework Gladiator or a Bunkerbeast are good monster Sentinels as they have high HP and resist status ailments . One way to start the battle is with SYN / SYN / SEN and buff while Yomi ' s attention is drawn to the Sentinel . If the party has Goblin Chieftain they can use his Feral Link to buff from the start . After being buffed the party can switch to a paradigm with Saboteurs and debuff Yomi . Poison drains Yomi ' s HP fast , seeing as Yomi has such high max HP , but it is difficult to get it to stick . If the player wants to poison Yomi they should focus one character on casting Poison until it works . Imperil is another useful status to apply . If the player doesn ' t want to use Poison , they can just debuff Yomi with Deprotect and then attack with physical attacks , but one may as well apply Deshell and Imperil to speed up the process . When Yomi uses Impenetrable Aura it heals itself from all ailments and starts restoring its HP , but once it gets out of this state the player can start spamming debuffs again . Whenever the party loses the buffs due to Putrescence the player should switch back to SYN / SYN / SEN . The best moment to heal is when Yomi uses Impenetrable Aura . The Sentinel can be useful for most of the fight . If Yomi uses Wicked Whirl the party should switch to SEN / SEN / SEN to minimize damage and switch to MED / MED / MED to restore HP .