Trigger-like. Continuous. If a face-up "Stardust Dragon(s)" or Synchro Monster(s) that specifically lists that card in its text you control leaves the field to activate its own effect, or by its own effect: You can apply 1 of these effects, also you cannot apply the same effect of "Majestic Mirage" again for the rest of this turn. Special Summon 1 of those monsters. Banish 1 monster your opponent controls or in their GY. All damage you take this turn is halved.