Incorrect again chuckles. Arthas was "LED" to Northrend by Malganis so that he could become one of the Lich Kings servants.
I'm not sure if you are Ironically quoting the Azshara part since I didn't leave it out, but again, no incentive without Sargeras being the one who pulled the puppet strings.
Sorry, but "Judgment" (Learn to spell please) has yet to be passed. I have invalidated you once again though, I think the Jury will side with me.