"Christ is king". I'm not Christian, but I'm saying it in solidarity. It is not stated in vain, because it serves a purpose, it was not all in vain, because it begets results. Trolls mad. That's a valid result; speaking down to blasphemers and heretics.

Hell, "king' is selling the incarnate godhead short.

Two thoughts. First, saying "Hell" here is highly ironic. Second, that's the standard title. "Glory to the newborn king". "The lord is my shepherd" (lord is a nobility pronoun). "Christ the lord". All very common parlances in standard Christian song and rhetoric.