As it often is the case with fighting bosses in the middle of summer holidays season, the main struggle here was not so much the encounter itself, but coming up with a setup that stood a chance beating the boss. Once we managed to do that, we did not need to wait very long for a kill.
Now that the semi-easy part of Tomb of Sargeras is cleared, the real deal starts. We already tried Mistress a few times and we now it is not going to be pretty.