LUCIFER
Not once has he entertained the idea of mentioning her past life to the current her. While hanyous and evolved humans exist in this lifetime. Talk of reincarnation is a good way to make people label you as a crazy person. Moreover, he doesn't want to force her to remember. Their bond still exists in this life, so it won't be long before she remembers. At least that is how it's supposed to be.
They are supposed to find each other as children, and he did find her. He found her before her parents locked her up in the facility. But on the day he was formally going to come over and explain the situation. Sumire lost control of her abilities, attacked a servant and her parents forced her into that damned place.