I think Chloe does not need to be an angel to have power over Lucifer.
Lucifer for the first time in his entire life found someone that did not see him for his Tittle or Job but for who he really is and as he said in the show " Something different about her that I don't quite understand, and it vexes me".
From my point of view he has issues and he needs to put them into perspective and admit who he really is and what he is because until now he is trying to prove "his innocence about rebeling against his father" and he tries to prove that he is the Devil and Chloe when she is not believe him. He is not only the one and not only the other he is BOTH . With that being said does not necessarilly means that doing the above is going to be part of his fathers plan he can easilly do as he pleases afterword but only then he is going to have true Free Will he wants because it is going to be HIS CHOISE.
He is falling in love and to rise again he need to fall again (become) even more human.Love yes can make you weak and vulnerable but also can make you even stronger and indestructuble.
Mazikeen was keeping him back always telling him how good and nice there were together in Hell and doing excactly whaat his father force him to do but Lucifer has gone beyond that.He wants to be on earth and do what he likes to do, with his own way and when ever he want to. Chloe gave him that by allowing to him to be his partner and that is going to help him involve, move on in a way breaking the shacles he put on him self.
Chloe is the representation of what we humor on the internet "Faith in Humanity restored".
What the world would be if all of people having those traits,these little things that make the difference around us? What Lucifer would be without the sins of people?
I dont mind seeing Lucifer becaming more human,get hurt,becoming the douce or humiliated but I am anticipating to see how and when he is going to rise.
The above thought of mine made but what i have seen till now, I might change my mind if proveb wrong or adjust in the future story as the show goes on.