Encountered in Viper Manor, when Serge, Kid, and their guide seek the Frozen Flame, they find the Dragon Tear on the General's Desk. Amused by the presence of Kid, Lynx provokes her anger, causing Serge to jump in and assist her in a battle against him. Throughout the battle, Lynx procrastinates attacking. He will occasionally strike once with his weapon in preparation for the casting of BlackElements. HellSoul and HellBound are used most often by him, to which he directs almost exclusively at Kid. HellSoul prevents her from being Revived should she perish, and HellBound causes her to perish with one move. Should the battle last more than a few turns, he will start with HellSoul and move to HellBound, so use Pilfer as quickly as possible to loot the Magic Ring or Power Glove, two accessories worth the effort of using an entire turn. Beware, however, as he will also cast Imbecile on to her to debuff her looting ability. Since Lynx seems to target Kid exclusively, use her elements and physical attacks as close to the beginning of the fight as well. Should he use HellSoul and HellBound on her, it may be wise to reset the game and start the battle over (there is a Record of Fate outside the room where he is fought, so save there beforehand in case the battle runs sour). Otherwise, exploit White Elements and Techs on him from the start of the battle, especially Dash&Slash and Meteorite, which should be allotted at least once to at least all three party members before the fight. Make sure to grab the Revive Element in the basement on the Manor, near the room containing Glenn and the other resting Acacia Dragoons, although the Element is useless should he cast HellSoul on a character. Remember to keep Hit Points high and the battle should run smoothly, with or without Kid. Along with the aforementioned Techs, Lynx also casts Brimstone, a high-powered Red Tech which strikes all players and is extremely effective against Pierre, should Serge have acquired the Hero's Medal and brought him along to the Manor. Also, he casts AntiWhite immediately upon Serge to prevent him from using White Elements, but it wears off in a few turns.
After the battle ends, a shadowy representation of a cat appears and laughs at the party. Evidently, this boss was not the actual Lynx but a Shadow Illusion, which may explain why it is able to cast a Red Tech when its Innate Element is Black.