I've been working on a Necro design myself and I couldn't get it to fit in the lore. I mean you can come up with an excuse for anything but some things are just too much of a stretch and Necros I think are one of them. So I reskinned everything to a Void Mage which worked pretty well, the design is kind of similar to yours in a way. The only aspect I couldn't really get to fit is the tankiness which is one of my favorite aspects of the class so meh. But expendable minions and dots, no problem.