[Mike hates seeing him start to cry. He wants to brush the tears away but Katsuki is already doing that with his new clawed fingers. His heart breaks hearing the way he refuses to listen and feed. He knows it is so much easier for him to say than for Katsuki to hear or even think about but it is a reality. One that is crashing down on his son and threatening to rob him of his greatest dream and his life's purpose.]

Son, not all vampires are villains. There are good vampires too. Just like there are bad ones. You don't have to hunt people to feed.

You can talk to people. You could ask if those you know and are close too would be willing to feed you from time to time. We can see about bagged blood and how that'll work. Or even animal blood.

There are options. ...But refusing to eat is what is going to get you to hurt someone really bad. Refusing to eat is going to let the hunger take over. It won't be you. It'll be like some animal wearing your skin and all you can do is watch as it chooses the blood instead.