Was originally planning to go in Stormblood maining Monk, since it looked to be a major focus much like how the Dragoon was at the center of Heavensward.
But now with the revelation of Othard being a major part of Stormblood too, not just Gyr Albania, I'm not too sure.

I only had a couple classes all leveled and geared by the time that A Realm Reborn was at its finish, but come the climax of Heavensward I've got everything leveled and geared, so really not sure how I'll proceed going into the new expansion. Yoshi-P's comments were to the effect that Stormblood will be evenly split between Gyr Albania and Othard, so tentatively I think that I'll level and main Monk and Samurai simultaneously; using each when in the respective locales of their origin. Then I'll level Red Mage alongside everything else on the side.