Honkai Impact 3rd: From Cocoon to Finality

The protagonist, Lin Feng Denoynlei, is a survivor of the Second Honkai of the Previous Era. After Elysia saves him, he joins the Fire Moth and later becomes a MANTIS. During the battle against the Herrscher of Domination, he gradually learns about his origins and leaves the Fire Moth. When the Herrscher of Finality is about to emerge, Kevin invites Lin Feng to fight alongside him. After they are defeated, Lin Feng enters a hibernation pod and survives into the Current Era. He witnesses many events in this new era. Later, Theresa invites him to teach at St. Freya Academy, and the story unfolds from there.