Elnath is a significant character in the anime Wish Upon the Pleiades, whose true nature and role are revealed gradually throughout the story. Appearing as a young boy with an ethereal quality, Elnath has blonde hair that is cut short to his ears and bright blue eyes, typically giving him the appearance of a teenager. His origin is not of Earth; he is a Pleiadian, an extraterrestrial being from the star cluster known as the Pleiades. Elnath’s primary mission is to gather special objects known as engine fragments or Potentiary Crystals, which are needed to repair his damaged spaceship.

In his original form, Elnath is a mysterious and well-intentioned figure. His personality is defined by a sense of purpose and a connection to his mission, yet he also demonstrates kindness, particularly in his early relationship with the human boy Minato. When the two first meet during Minato’s childhood, Elnath enlists the boy’s help in searching for the crystals he needs, indicating a collaborative and trusting nature. However, this partnership takes a tragic turn. When Elnath’s power runs out during an attempt to capture a fragment to grant Minato’s wish, it is revealed that Minato has actually been in a coma. Unwilling to accept this reality, Minato rejects Elnath and his offered destiny, casting him aside as he becomes consumed by darkness.

Elnath’s role in the main plot is deeply intertwined with the fate of Minato, who is later revealed to be the caped boy collecting fragments for himself. For a significant portion of the story, Elnath’s whereabouts are unknown. In a pivotal twist, it is disclosed that Elnath has been present all along in a different guise: the President of the Astronomy Club, who has been aiding the magical girls. The President is revealed to be Elnath transformed into a small, wobbly, mollusk-like creature who has lost his memories of his past life and his history with Minato. This form highlights his enduring, if obscured, desire to help and guide others.

The central relationship in Elnath’s story is with Minato. They share a profound history as former companions, which turns into a source of conflict when Minato abandons Elnath to pursue his own dark path. Their bond is further complicated by Minato’s romantic feelings for Subaru, one of the magical girls. By the end of the series, Elnath’s connection to Minato is repaired. After the girls and Minato succeed in retrieving the final fragment from a black hole, Minato makes amends with Elnath, finally accepting his fate and their partnership. With his spaceship at last completed, Elnath is able to fulfill his mission. He departs from Earth to travel to a new universe, carrying on Minato’s original goal of saving potential lives and exploring new possibilities.

As a Pleiadian, Elnath possesses abilities far beyond those of an ordinary human. His primary power is related to the engine fragments, which he seeks to power his ship and which are connected to the realization of wishes and potential. His power is not limitless, as shown by its depletion leading to the revelation of Minato’s coma. In his true form as a humanoid boy, and even in his disguised form as the President, Elnath exhibits a deep understanding of the cosmos, singularities, black holes, and the fundamental forces that govern reality. His final act is to send the main characters back to the beginning of time, offering them the chance to choose different potentials for their lives, before he himself departs for a new universe.