|Common Drop||Rare Drop||Common Steal||Rare Steal|
|Lv. 3 Key Sphere||Lv. 3 Key Sphere||Stamina Tablet||Farplane Wind|
The fight against Yunalesca takes part across three forms and it’s definitely one of the tougher battles in the game. The first form is pretty easy, as Yunalesca will only have two moves in her arsenal. Her normal attack is quite weak, but the catch is that it removes buffs from the character it hits, except for Reflect, Regen and Auto-Life. The other attack she does is Absorb, siphoning health from one of your characters and healing herself. Note that Absorb always targets the character with the highest current HP and deals damage equal to half of the character’s maximum HP.
So, the first form seems easy enough, but Yunalesca can counter all of your attacks. If struck physically, she will counter with Blind, while magical attacks are countered with Silence. Other attacks that don’t fall in with the above are countered with Sleep. It’s noteworthy that these counters are actually spells, so it’s possible to reflect them back, although they won’t do anything to her. So, it’s possible to start the fight by casting Reflect on everyone, to avoid not only the counters, but also some stuff with the later forms. Also, the Sensor description says she is vulnerable to holy magic and while it damages her, she is not weak to Holy.
Upon reaching the second form, which includes a transformation, Yunalesca will use her first turn on Hellbiter. This does some damage to your characters, but it will inflict Zombie on the entire party. You should leave this alone, as it will be a help with the third form, so don’t remove it. Should you actually remove Zombie, there is a chance that she will use Hellbiter again. While your characters are Zombified, Yunalesca will cast Regen and Cura on them, causing damage because of the Zombie ailment. Once again, these are spells and if you kept Reflect up from the previous form, they will bounce back at Yunalesca.
Of course, you don’t want Regen on her if you reflected it back, so make sure to Dispel it. Note that she doesn’t use her normal attack now, besides as a counter, which still have the dispelling property. Also, Absorb will only be used against Aeons. Upon reaching the third form, Yunalesca will use her first turn to cast Mega Death, a skill that instantly KOs any characters not afflicted with Zombie or have Deathproof on their armor. Mega Death is the sole reason you will want to keep Zombie on your characters from the previous form. Besides the above, she will retain Hellbiter, as well as Regen and her normal attack counter.
Yunalesca will upgrade Cura to Curaga and start doing a new move, Mind Blast. This will have a chance to inflict Confusion on characters, plus it also inflicts Curse on Aeons. Speaking of Aeons, Yunalesca can now use Osmose on them, in addition to the Absorb from before. She can also just use Hellbiter whenever she wants now, instead of waiting for one of your characters to be cured of it. As you can see, the three forms of Yunalesca kind of compliment each other, especially the second and third forms. You will want to keep Zombie on your characters because of Mega Death and possibly put Reflect on everyone to bounce back the healing spells.
Also, despite not actually being weak to Holy, one of those thrown at Yunalesca will likely do the full 9,999 damage, especially coming from Yuna or Lulu, who should have a high magic stat. If you have Rikku’s Overdrive full at the beginning of the battle, have her steal a Stamina Tablet from Yunalesca (the common steal) and mix it with a Potion. This will net you Mega Vitality, a mix that doubles all active party members’ HP. Having the extra HP will definitely help in the second and third forms, as healing will be an issue with Zombie. Keeping buffs on your characters is also problematic, because of her normal attack dispelling buffs.