I was a Venthyr Blood Elf Paladin on the Hyjal server with my Hearthstone set in the Covenant Sanctuary, I swapped to Kyrian but did not move my hearthstone out of the previous Covenant’s area. Now when I hearth I am ejected out of the Revendreth Sanctuary properly however my character is left invisible on the client side. I confirmed whether this was server side or client side by asking another player what my gear looked like and they responded correctly.
I performed actions that would make my character become visible temporarily. Once that action/animation is complete a Venthyr style blood teleportation animation takes over my character that leaves me invisible as if I were to walk into a blood mirror or use the Venthyr teleportation ability.