Set in Western Europe during times of war, Eleanor "Ellen" Vertalia, one of the Vanadis of Zhcted, leads the battle into Brune. There are, in fact, seven Vanadis, each having received a powerful weapon from the Black Dragon to reign over one of Zhcted's seven territories. The power of the Vanadis invokes dread and fear in their enemies.
An earl in the service of the country of Brune, a young archer by the name of Tigre, experiences the Vanadis's power firsthand after being defeated on the battlefield by Ellen. However, Ellen chooses to spare his life after witnessing his skills, but in exchange, he is asked to serve her.
(Source: jCafe24, edited)