So each one brings not only a potential fan-favorite to play, but a new style of game play.
Also, they're introducing a new epic mount, an Elemental Stag.
Probius is due to be on the Public Test Realm this week, I'd expect to see the Elemental Stag.
https://youtu.be/8C8beOn1QesVideo can't be loaded because JavaScript is disabled: In Development: Probius[...]