Demon World Castle, Totwachter

(This ability is active if you have one or more face up G units in total on your or G zone):[Choose one of your grade 1 rear-guards, and retire it] When this unit attacks a vanguard, you may pay the cost. If you do, this unit gets +5000/ +1 until end of that battle. :[ 1 & 1] When this unit is placed on , you may pay the cost. If you do, search your deck for up to one grade 1 card, call it to , and shuffle your deck.