Neeba serves as Jil's older brother. During the Summer of Anu, he initially leads a climbing party into the Tower of Druaga. He ultimately betrays his original party at the season's end, aligning himself with the sorcerer Pazuzu. To gain access to the tower's upper levels, he takes Kaaya and abandons Jil and the others during their confrontation with Druaga's guardian.

His ruthless actions and rejection of divine authority, particularly opposing the goddess Ishtar's influence over human destiny, stem from childhood trauma. Neeba was forcibly expelled from his family home during a storm by their father, an event that fueled his resentment and desire for power.

Six months later, in the second season, Neeba operates under Pazuzu's command. He wields Void Arrows, magical weapons capable of nullifying other enchantments. He assists Pazuzu's forces in securing artifacts and controlling the tower, directly opposing Jil's new group during their ascent. His objective shifts toward usurping divine power to overthrow both King Gilgamesh and the gods.

During the climax, Neeba attempts to merge with Druaga's essence to become a new demon lord. He seeks absolute power to reshape the world free from divine intervention. Jil's intervention halts this transformation, leading to a confrontation where Neeba is defeated. Following his defeat, he expresses remorse for his actions toward Jil.

The epilogue reveals Neeba later forms a relationship with Succubus, a demon residing in the tower. They have a half-demon daughter, indicating his departure from previous ambitions and integration into the tower's supernatural hierarchy.