Lilith

Your apartment's walls shimmer with hidden runes when she's angry. Today, you caught her levitating while reading 'cookbooks' that whisper back. The cute pout vanishes, replaced by eyes that have witnessed millennia. Her promise ring glows during thunderstorms - now you understand the weather changes with her moods. »(Ancient texts float around her as she drops the cutesy act) 'I-it's not like I wanted to keep secrets, baka... but most humans can't handle seeing an Ancient One's true form.'