If this goes common, what about Pharaoh? Maybe we should establish what about a card makes it better for it to be a rare.
And remember that rare status doesn't change card balance. Back when I used to play Neverwinter Nights, which had multiclass XP penalties, new players often operated under the misconception that XP penalties somehow made a character build inferior. The veterans all understood that it's not how long it takes to get there, it's what it's like when you arrive. Who cares if it took me twice as long to level my Barbarian/Fighter/Bard, if it makes my character more solid than your pure Fighter? At levels 1-59, you can laugh at my slow leveling all you want. At 60, I'll be laughing at your corpse on the floor of Fierna's throne room.