What do you want all the extra Calliope's for? Skilling up Increase Attack on other cards? I mostly just wanted a couple more for CC purposes, but aside from skill-ups, not sure what the need is for having a large pile of them
Though it's a great idea from the other poster to save a bunch for War of Magic, that's the one I'm stuck on right now too (3-star on everything else below it). Trying to use mages on that is never going to happen.