They Regretted It After Draining All My Blood

The richest man's son came down with a strange illness and needed a complete blood transfusion.

As the only person who was a match, I was forcibly adopted and imprisoned by them.

They used my mother's life to threaten me, draining all my blood again and again until I died.

After my death, the richest couple felt no remorse.

"So what if he died? Being adopted by us was a blessing he'd earned in his previous life!"

Then they discovered that the son they had cherished like the apple of their eye was actually the bastard child of a rapist.

And that I was their biological son.

They went mad.