Knight of Erin ナイトオブエリン

Under the pact with a demon sword, she is destined to be mightier by having sex. The story Follows Erin; a mercenary who was mortally wounded in the past and was forced to accept a pact with the demon sword Nighthawk. Our story begins with Nighthawk and Erin infiltrating a castle under the cover of night in search of something for Nighthawk’s sister…​