Grey is emotionally unavailable at the start but is shown to be sweet at times and demanding on others and she has a hard time reading him. This is why Anastasia was thinking how Grey has multiple shades (hence 50 shades of grey). Part of the appeal for Grey was his 'bad boy' vibe (and also being a billionaire who showered Anastasia with gifts and helped with her financial situation). It was even stated Grey 'doesn't do love, he fucks'
but after finding out that Anastasia is a virgin, he decided to 'make love' to her. And still he is shown to be caring and goes after her when she decided to cut things off at start. Part of his journey is letting himself be vulnerable and letting his childhood abuse release its hold on him. Just compare how despite the books' focus on sexual freedom and 'bad boy being kinky and hot', the depiction of the female lead and her dynamic with her 'dom' is still more romantic and intricate than Lena's path of 'bad boys'. And 50 shades is a middling smut despite its popularity.
EDIT: Also who the fuck is Dorian? Are you confusing Christian Grey from 50 Shades of Grey to Portrait?