What artifacts could be added to the next expansion pack?

By the way, the topic title isn't entirely accurate. If there are any future installments, it will be Heroes VI (Kingdoms and Online don't count), but that will be a sequel, not an expansion... Never mind.

A few more good artworks wouldn't hurt, but they need to be original, as IMO it's no longer interesting to create artworks that simply increase attributes; there are already plenty of those...