My Vampire System: A Dragon's Revenge

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 afterlife—hmm? I was reincarnated as a weak human baby?!!