The answer is none. BLU breaks the mold on the scripted content Yoshi P puts out which is why they keep it 2 expansions behind.

BLU can play differently based on the situation whereas the other classes are boxed in to only really play one way.

As a result the 19 limited jobs are boring while BLU is versatile and exposes the combat system for what it really is.

The gatekeeping on PotD and Eureka is some funny ass shit considering some of BLU's BiS gear can only be obtained in Eureka.