The Masters group are the most dangerous of all the creatures in the game. Luckily, they're not as common as the other groups except maybe dragons.

They use use equal power and psychic ratings like the dragon's but unlike any other creature types, they attack both physically and psionically on the same segment of combat making the very formidable adversaries. Like dragons, they are quite stubborn and rarely run from a conflict. There's a couple minor B & C class masters with some D but class E & F is where most of them hang out. Here's a few examples of the masters:

Class B

Class C

Class D

  

Class E

     

Class F