Ramsay character is one that in my opinion is under-appreciated as his growth and potential appear limitless!(well, limitless in degree of evil). He is better than Littlefinger at Littlefinger's own game and would make a great antagonist to any mortal* hero character. Surely there are Ramsay haters - as there should be as this is the entire point behind the Ramsay character (pure evil incarnate) - but for the most part, he should proceed to the top of mortal conquests (evil oriented). I suspect that he sides with the Others (as they are merely another tool of evil Red money from Braavos - but we're going to have to wait and see how these things develop. Oh, btw, while the green folks are using weirwood.net as their command and control communications network, Braavos War Machine Inc. is using lavetube.net (the 3 cinder cones in King's Landing, a local network of sorts) as a means to remote view and control things at the tactical level towards achievement of their theater (Westeros theater of operations) strategic goals. I suppose they also do this in Essos with Dany, through the use of Red Priests/Priestesses. Those ruby Red neck pendants, gemstones in kind crowns, castle gates, even the metal/gems in swords, are part of the redwildfire.net super network trunkline.
His is the prototype for the wars to come -and Iwan Rheon is the prototype for the roles to come! I suppose Iwan needs to be careful not to be character-cast as the bad guy- of course he could make some nice jingle in those roles if he were to pursue that angle.
So, in traditional sci-fi Ramsay's (Ramses) character arc should be through King's Landing and then to Volantis (world capitol) - as he has outdone Littlefinger - he is under-appreciated by fandom - his character represents the truest of evils and he is really a military-industrial complex manufactured evil flesh incarnate by the money-taking big war machine - the price a liege Lord pays after selling out his wife -Roose's first/second wives.
Ramsay's Glidepath to Conquest
For really good science fiction, I would hope both the books and show take this route - but hey, I'm not the writer - and I'm very happy with GRRM's & D&DW's approach - this is traditional Heinlen, Vancian approach.
I just hope that Ramsay doesn't meet his Waterloo at Winterfell.