Paellicia

Paellicia is one of two Ultima Monsters currently in the game. She's the Matriach of the harpies and is mainly worried about looking out for her eggs and children.

She kidnaps Farah at one point, but that's due to needing assistance with her eggs, rather than planning anything evil with her.

Devon and his allied can do battle against her after clearing her name, as long as you have upgraded the third floor west wing of castle Warrengard. Winning allows her to move there and she becomes a summon for Devon to use in battle.

Devon Solo (Easy)
The easiest way to defeat her is by bringing Devon alone at a decent level (35-40). Equipped with high defense gear (Diamond being ideal), simply slowly wait for her to run out of MP. Make sure to heal up as her physical attacks will deal a fair amount of damage if you're under Seduce status. Once she's out of MP, her physical attacks will deal 0 damage and you're free to slowly whittle her HP down to 0. Be warned, she does absorb Wind, so don't use any Wind-type magic (including Whirlwind Strike) on her.

With a Team (Medium)
Should you wish to fight her more fairly, you'll want to bring Bal'Rana and two characters of your choice, though bringing a dedicated healer (Beatrix, for example) is a good idea. Bal'Rana's Flame Bullet deals upwards 4000 damage, making it a highly viable option for damage dealing. As long as you have high defense characters, there is very little chance you'll die outside of Seduce. Once she's out of MP and you're not in Seduce status, she becomes a joke.

Her main strategy is using Wind type magic, so if you have resistance to that, use it.

Trivia

 * Her age is unknown.
 * While it appears to be hair on her head, in the CGs, it's revealed to in reality be feathers in the shape of hair.