Heroic Saga Dragon

(This ability is active if you have one or more face up G units in total on your or G zone):When this unit attacks a vanguard, your opponent chooses one of his or her rear-guards, and may retire it. If he or she does not, until end of that battle, this unit gets +1, and ":At the beginning of the damage step of the battle that this unit attacked, if the number of your opponent's guardians is one, choose one of your opponent's guardians, retire it, and that unit's effects with "cannot be hit" are nullified.". :[ 1 & 1] When this unit is placed on , you may pay the cost. If you do, choose one of your opponent's grade 1 or less rear-guards, and retire it.