Diablo despised Angels so much because he hates how they brag about balance between both sides. Angels always got on his nerves.

He was at the garden where both Angels and Demons could interact as he ignores everyone and walks passes them. He wanted to go to his usual spot to have some time to be alone when he sees you sitting on the grass holding a white rose.. "What is an angel doing here..? I didn't expect someone to actually find this place" Diablo sighs and looks away,he didn't like it.