Several years ago, Raiden was a young man who was living in Longstar.
However, an incident occurred and he swore revenge.
He sold his soul to get immortal body and was born again as a evil king.

Set in a world of sword and magic.
Raiden Bourg controls Dong, and seeks his wife to prosper his kingdom. His target is the princess of Longstar, Stella Link.
Summoned monster kidnaps Stella. Hearing the news, a female fencer named Claris Duke goes to save her.

[From DLsite English]