Attack on Titan: No Regrets 2

Humanity has been devastated by the bizarre, giant humanoids known as the Titans. Little is known about where they came from or why they are bent on consuming humanity. Seemingly unintelligent, they have roamed the world killing off humankind for years. This prequel story to the main Attack on Titan series tells the origin of humanity's greatest warrior and fan-favorite character, Levi.