Age 16, Asuka Tachibana is a member of HOLY. Tachibana has a sweet demeanor when he's not fighting, but when conflict arises he becomes stern and professional. Early in the series, a bitter but unrequited rivalry with Kazuma rises after he is embarrassed by Kazuma during his escape from HOLD headquarters and a subsequent battle in which he is almost effortlessly defeated. When the two are later trapped in an underground cave, he is given new insight into the ideals of the native Alters from Kazuma.

Asuka's Alter is "Eternity Eight" or the "Eight Treasure Balls", eight small emerald orbs that act as an extension of his will. One of the most versatile Alters in the series, his Eternity Eight can arrange themselves in different patterns and form various energy constructs: a sword, a shield, a platform to ride on, and so forth. They can also be used in singular form for precise actions. Asuka can control the minds of living beings using his Eternity Eight by attaching the orbs to his targets, although some Alter users can resist this effect by force of will. In addition to the orbs, Asuka can manifest a bow to fire his Eternity Eight as an arrow, called the "Eternity Extra Shot".

(source: Wikipedia)