The Icebrood Saga came out this year but I unlocked Crystal Champion prior to this year. In fact, until just recently, I hadn't logged into this account since December 2018. I THOUGHT, perhaps wrongly, that those skills were unlocked when I was doing things with Aurene, in Tarir, during LS 3. It might have been a coincidence though. In any case, I did the prologue of the Icebrood Saga with my other account and Crystal Champion wasn't unlocked. Guess I'll have to do at least part of LS 4. I really just want the dismount Mastery.