Weiss is a young man who was given the responsibility of being the Spirit Vessel after committing the sin of killing a god. His memory was all but destroyed, with only the knowledge of his name remaining. It was only when meeting the mysterious Eva does he learn of his crime of deicide and of the penance that had been given to him, which is to retrieve the fractured power of the god and store it within himself in order to resurrect the god he had slew. He is often bothered by the violent and brutally pragmatic decisions he is forced to make. However, it is during these crises of the soul that glimpses of his past self emerge.