Immune to Rewind!! :]
Not actually... 1 mummy needs 3 supernovas to be played, same as 2 recluses. Against 1 rewind, you may play the recluse again and mummy becomes a pharaoh, but against 2 rewinds, instead of having a chance of playing the recluse again you will get a useless pharaoh in your hand... pretty crappy.