E4 functions as a Hikarian, regularly partnering with Max due to overlapping operational responsibilities. In the original series, the character exhibits sparse dialogue, maintaining a reserved presence that contrasts with Max’s comparatively vocal demeanor. This dynamic evolves in the sequel series, where E4’s dialogue frequency rises markedly, reflecting a deliberate shift in communicative expression. Collaborative missions with Max form the core of E4’s role, though specific narrative arcs or personal history remain undefined. Joint duties prioritize teamwork, though the exact scope of missions and individual contributions are not detailed. The character’s development is documented solely through television series portrayals, with no confirmed appearances in films, OVAs, or spin-offs.