A Breath in the End of Verdure

After a cosmic accident lands her in another world, Jiwoo Seo is resigned to living as a whole new person. She has spent the past five years purging her new world of demonic energy as Akarna, a being who must sacrifice her blood and her freedom for the empire. But when the man she loves gets engaged to someone else, Jiwoo flees from her gilded cage. Rescued by a stranger from a clan of beautiful, otherworldly men, they concoct a plan to keep her safe—by having her marry them all.

Source: Tapas