Unique faction gameplay and FOUR new lords to boot, this dlc is pretty rocking. Kinda expensive for the content, but thats pretty much anything with a Games Workshop tag.

The army plays pretty fun with weak bulk units alongside overpowered big units and an interesting summoning mechanic based on your own losses. I find the Tomb Kings to have a lot better unit mix synergy and require a bit more managment than some of the other factions, but the victories feel more statisfying as a result.

Have not tried Mortal Empire with them yet but see a problem with army and unit limits that might hinder their ability to conquer and hold the expanded campaign map there.

Worth it if you enjoy new armies and variety, price is a little high though if you are only casually passing through this game.