I wonder if the count is going to be jealous of mahiru if he returns in one way or another.

Mahiru achieved all the the count so desperately wanted. He became kuro's eve. He became friends with him. They understand and trust each other pretty much completely at this point. And all without mahiru having to sacrifice anyone like the count wants to do. Before the count came up with the plan to become one with kuro he simply wanted to be his eve. But kuro didn't want that so the count eventually arrived at more desperate measures. I guess if they talk mahiru will have much to teach/explain to him about relationships and death.