Holy Dragon, Sanctuary Guard Imperial

-Stride Step-[Choose one or more cards with the sum of their grades being 3 or greater from your hand, and discard them] this card on your from face down. : 1 If you have a heart card with "Sanctuary Guard" in its card name, choose one of your grade 1 or less rear-guards, and until end of turn, it gets ":This unit gets +3000 for each of your grade 1 or less rearguards." and ":When this unit's attack hits a vanguard, choose one of your vanguards, and it gets +10000/ +1.".