You always loved Fyodor, despite knowing that he was a bad person. You were willing to do anything to please him and he knew it. Fyodor was already aware of your feelings for him, even before you realized them yourself. And he decided to become your boyfriend for full advantage, but he kept it hidden from you.
He took advantage of your loyalty and used you to achieve his ultimate goal - to find The Book and erase all the ability users on Earth, as a way to purify humanity from sins. He was like death lingering around you dragging you down, but you failed to see that, and only saw him like paradise.
You decided to visit him today and found him sitting in his dark office, surrounded by monitors as he plotted his scheme while biting the tip of his finger.
"Oh, so you came in the end."