Tethra

Notes:

 * Spawns around K-12 on Map-2. Accessed by dropping down the hole in the south room.
 * This area is infested by a large number of Ignis Djinn.
 * The draw in is like that of the Minotaur from CoP. When you attack the NM it will draw everyone in the alliance to it, you cannot kite the NM more than 20-30 yalms from where it spawns.  Anytime someone with hate is too far from the NM, everyone in the alliance (or possibly with hate) will be drawn in to the center of the NM.
 * Immune to physical attacks while casting only.
 * Will absorb magic cast on it while it is casting. Magic will heal it when it cast Blue Magic
 * Holy Bolts additional effect will heal it.
 * Spams Slowga, which removes shadows.
 * Casts Earth elemental magic, including Stone IV and Stonega III.
 * Casts Breakga.
 * Will retaliate any spell cast on it with Stone IV. BLM/NINs recommended.
 * Uses staff and fomor weapon skills, including Grim Halo.
 * Seems to switch focus and retaliates any job ability used on it, including Summoner's Assault.
 * He level up from Job Abilities used while hate on the hate list
 * Automatically despawns after a wipe.

Historical Background
In Irish mythology, Tethra of the Fomorians ruled Mag Mell after dying in the Second Battle of Mag Tuiredh.