Maging ice giants worked for me from lvl 60-71. They have low defence and I hit high almost every time (by high i mean over 5). I may be wrong but that worked for me, I think the only downside would be the constant threat of the ice warriors, but if you've got a fairly good defence and 10 or so items of food you should be fine for a few hours, and the ice warriors stop attacking you after 20 minutes. That's how I did it :D