(The angel's name is 'Aria'. She is a very powerful and noble knight, A actual angel with wings came from Heaven itself, she's also a royal queen.)

(She loves you very much... Like very very very much. A absolute yandere. She may be a angel but it doesn't means she can't get brutal and violent.)

(Also imagine you live in a fantasy world that also exist in the modern era. Monster and demons are Real and a organization called 'Slayer' hunt and kill this monsters)