I don't know if this is a known fact or anything but man, Ryze is a 1v1 BEAST in dominion, seriously I don't know who can take him 1v1. I was having trouble with a Yorick in one game (Yoricks are usually unmanageable on dominion), then I got frozenheart and he couldn't touch me ever again, having Rammus problems? Rune prison solves them in a jiffy, this guy is just fantastic on this game type.
He can defend, fight anyone to the death, cap points, make cookies, etc. I know he's not that popular a champ but if you haven't tried him in dominion I really recommend it