Yeah, you should get all the Raid hime eventually because of Raid tickets. I missed quite a few early on, but I think I've got all of them now - you should get two tickets off Stolas for example.

Despite my earlier comment, I think you were probably right - Diana is probably the right hime for you from the MTix, especially as there's Dark Tower running. And remember, whatever you pick - the game will give you something to make it irrelevant to you. But that's the real fun for the game - working out how to combine mismatched hime to get some synergy that will give you an edge.