I think Diana is still trying to get a basic understanding of what her Circle actually means. There may be some intuitive understanding that she shares with Charles, but that could only be revealed a little farther down the line.
Dawn does seem to have a very clear strategy, and she's very effective at manipulating Charles to serve her plans. The backstory for that will be interesting to learn. That being said, are they actually after the same thing? Hard to say. With these characters, I think all assumptions are very unsafe.
Harold also revealed his ultimate goals.
I think it's probably power first, because that will ultimately give him the power to protect Diana.
Source: TV Fanatic