Manga by author JkSManga

I was once the legendary red dragon who stood at the top of the world. For thousands of years, my brethren have been murdered by humans and the desire for revenge slowly turned into my only mission in this world! However, I failed. On the day of the decisive battle against human beings, I died with hatred in my heart... if there is an afterlife, I will definitely avenge my kind. If there is an afterlife, I will make these filthy humans pay with their blood! If there is an afterlifehmm? I was reincarnated as a weak human baby?!!

Death decides to give his youngest son his first-ever task, but instead of taking a life, he has to protect one instead. The problem is kai has never been to the human world and doesn't know how to act like one either. This means someone's got a Grimreaper as a bodyguard.

The Sound of the alarm triggering the lockdown is the last thing Sam can remember. Sam wakes up in the middle of his classroom to discover everyone around him is dead. With no memories of how he got there, Sam tries to figure at what could have happened, but Sam doesnt just have to worry about what killed his classmates, because even the survivors are after his blood.