F-Rank Soul Eater

Soul Mechas were forged to punish the Eldritch Monsters that attack this world from Beyond the Glass. But they can only be powered by those who bond with ancient mythical souls from that world. Unfortunately, souls are only attracted to negative emotions: helplessness, anguish, and loss. The deeper and more wronged, the better. However, regardless of the empire's pressure on the people to produce the best Soulbound Warriors and the heavy stigma from his father's curse, Soren remains a happy boy, a dreamer. Until he ends up with the worst soulbond in history after 'The Touching Glass Ceremony.' An F-rank soul. Trash even amongst trash. Even the commoners laughed when his rank was called. Beggars in rags celebrated and claimed to be above him. But was it really the worst soul bond ever? Because, when an Eldritch monster ravages their town and kills all that he loves, Soren finds himself repeating the same day again and again, bathing in unimaginable pain and death that forces him to grow, evolve, and confront questions that plague the empire, his father's mysterious curse, soul rituals, and the Eldritchs' true goals on earth. Each loop leaves him HUNGRIER, stronger...but less human. As the lines between man, soul, and machine blur, Soren must decide the very fate of the world...