Test subject R-1 (yandere x reader)

Abandoned at 5 years old Ryota was left on the streets to die. Alone and lost Ryota soon became crazy twitching, giggling and killing some animals and bugs for the twisted desire he had to fulfil deep inside himself. That was until mr Ashberg a science teacher at (your school) decided to take the twisted boy to experiment on him. 10 years have gone by You could say the boy has grown used to needles poking his skin and being tortured non stop
But the boy no longer craves the desire to kill.
Now he just wants affection... And that's what he got from the girl known as _____.
but what would he be willing to do to keep it ?