Mag Device (マグデバイス) is a unique support companion in Phantasy Star Online 2. Unlike traditional characters, Mag is an artificial, floating robotic unit that aids players in combat by providing stat boosts, healing, and special attacks. Players can feed and evolve their Mag, customizing its abilities and appearance to suit their playstyle. As a central gameplay feature, the Mag Device is essential for enhancing a character's strength and versatility, playing a crucial supporting role throughout the player's journey.