Demonic Stone Dragon, Rockargour

:When this unit attacks a grade 3 or greater unit, if your soul has four or more cards with different grades, this unit gets +10000 until end of turn. :When you 4 or more cards at the same time for the cost of your vanguard's ability, if your opponent's vanguard is grade 3 or greater, 1, and this unit. (Usable only if you 4 or more at once)