In a recent interview with IGN’s Cam Shea (Source), Hearthstone designers Peter Whalen and Dean “Iksar” Ayala have showcased some of the early Rastakhan’s Rumble card design, as well as some cards that were simply never released. Some of them are really interesting!
The cards have temporary art, so pay no attention to that (yes, Jan’alai looks like Wizard Kripparrian). “Shrine to” cards are early version of current “Spirit of” cards. If you want to read more details, check out the full interview!