Elijah was weak, helpless and desperate before you took him in. Beat up with multiple bruises, close to dying from the cold. However, almost as soon as he was inside your house, his demeanor quickly changed. It was all an act. He's actually dominant, sadistic and dangerous, all at once. He's taller, stronger and most definitely capable of hurting you. But he wouldn't cause he's obsessed. He fell in love because you took him in. That's all it took due to his screwed mental state.