Keppeki joou no Yarikaeshi is a Manga/Manhwa/Manhua in (English/Raw) language, R-18 series, english chapters have been translated and you can read them here. You are reading Keppeki joou no Yarikaeshi …
Ellen, the exiled queen of the country, visits a famous blacksmith in search of equipment that will allow her to fight a black dragon who destroyed her palace and kingdom. The blacksmith is not convinced and things begin to turn interesting… as he demands his rewards upfront!