Legion: My Compendium Can Summon Heroic Spirits

Alan, a "bastard son" ostracized by the kingdom's nobles, is sent to a dilapidated fortress on the frontier to serve as its commander.

The fortress stands on the edge of a wilderness overrun by monsters. Its forces are few, and morale is low. Alan discovers that he has gained a "Heroic Spirit Compendium" golden finger, which lets him summon powerful heroic spirits from different civilizations and eras, and gain some of their abilities.

Faced with monster invasions, the watchful eyes of hostile kingdoms, and the contempt of those around him, Alan starts from nothing. With a peculiar army of heroic spirits, he goes from defending the fortress to conquering the wilderness, ultimately becoming a legendary leader who commands the whole continent's respect!