Asmodian's Contract is a Manga/Manhwa/Manhua in english language, fantasy series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.cc fastest updating comic site. The Summary is

The demon lord's daughter Yurisina was living a normal demon's life when she was summoned by a human who was about to die. Not just any human, but the Paedin kingdom's first princess Marianne. As Yurisina lives on in her body instead, Marianne requests that Yurisina takes revenge on the person who poisoned her.