Perdition Dragon, Vortex Dragonewt

Perdition Dragon, Whirlwind Dragon :[ 2 & Choose a card with the same card name as a unit on your from your hand, and discard it] If this unit is Legion, choose up to two of your opponent's grade 2 or less rear-guards, and retire them. Then, if the number of cards in your opponent's damage zone is four or less, choose one of your opponent's vanguards, deal one damage, during that damage check, all trigger effects are nullified. This ability cannot be used for the rest of that turn. :During your main phase, when your opponent's rear-guard is put into the drop zone, this unit gets +3000 until end of turn.