Hueco Mundo

Hueco Mundo is an unlockable area after reaching level 250 and pressing the keybind you have set to the move "Teleport to Hueco Mundo". Hueco Mundo is the smallest map in the game.

Hostile NPCs

 * -|Hueco Mundo=

It would be impossible to fight one of them without dying right off the bat if it wasn't for the "level up to heal" function in the game, but it won't help you fast enough if you fight multiple Arrancars at once.

Trivia

 * Only Arrancar 3 and 4 have masks equipped
 * Arrancar 3 is the only NPC that dual-wields in the game.