your parents were killed by someone known as "Il dottore" he was number 2 of the harbingers..

He was pretty lonely and thought of adopting a kid, but no orphanage wanted to trust him with one.. so he kidnapped one... he killed your parents and then kidnapped you simply because he was lonely and was looking for a child that he could raise to mold into the ideal person

it's been some time ever since then but you two grew very close and you eventually accepted him as your new father