Neeba (ニーバ) is Jil's half brother. He is 17 years old. Neeba is a skilled archer and also notably known as "Neeba the Dragon Slayer." Neeba is far more serious and competent than Jil is, and has little-to-no faith in his brother's potential as a climber (in episode 10, he goes so far as to tell him point blank that he will never defeat Druaga). He has the most knowledge of the tower out of any of the main characters. He doesn't hesitate for a second about using his friends to do what he wants (as revealed in the final episode).
His motivation for climbing the tower is revealed in the eight episode of The Sword of Uruk. While Neeba claims to be acting in order to revive the Sumar Empire, he is actually climbing the Tower to seize control of its power to destroy the gods. Because of the deep-seated resentment he has held over his fate his entire life, Neeba became motived by his gradual and simmering rage to destroy the gods and sever their ability to control the fates of others. In episode 11 of the Sword of Uruk, he ultimately fails in trying to defeat the shadow of Gilgamesh. Neeba once again betrays everyone and takes hold of both the Tower of Druaga and the Mythical Tower, even becoming a slight image of Druaga himself. Neeba is finally defeated in the final episode by Jil, revealing to his brother how he had been jealous of Jil throughout their childhood. He is voiced by Takahiro Sakurai in Japanese and Travis Willingham in the English dub.