:When this unit boosts a grade 3 or greater unit with "Nebula Knight" in its card name, this unit gets
+2000 until end of that battle, COST [discard a card from hand], reveal the top card of your deck, if it is a trigger unit, choose one of your opponent's front row rear-guards in the same column as this unit, and retire it. Put the revealed card on the top or bottom of the deck.