Well Ring is something in between - we raise our rank to 5, and blood rank to 7. I would say that it is half power, half potential untill Azure is saved.Note that the example of a problem she can't solve is an Armament with a deployed shroud. Not being able to beat a rank 10 giant robot is not indicative of a bad option. I'd say the greediest option here is actually crimson flare since it doesn't conclusively even beat this old man and we don't get most of it's benefit until getting the ring.
Still I get your point so we can agree that in order of greed it is Stance<Gisena<Ring.