Great Hero, Rising Supernova (G-BT09/S06EN) [Divine Dragon Caper]

[Stride ]-Stride Step-[Choose one or more cards with the sum of their grades being 3 or greater from your hand, and discard them] Stride this card on your (VC) from face down. [AUTO](VC): [Choose a face down card from your G zone, and turn it face up] When this unit attacks a vanguard, you may pay the cost. If you do, choose up to the same number of your rear-guards as the number of face up cards named "Great Hero, Rising Supernova" in your G zone, they become charging, and if the number of your rear-guards that are charging is four or more, all of your units get [Power]+10000 until end of turn. (Units without charge can also become charging)