Her Guardian Devil

The mafia boss, a man of darkness and violence, finds himself unexpectedly falling in love with a woman who lives a simple life. He's captivated by her kindness and innocence, which is a stark contrast to his world. His love turns into obsession, and he's willing to use any means necessary to protect her, even becoming a monster to keep her safe and only for him.

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Cover not mine, credit to the rightful owner of the cover.