Sword Light Dragon, Sky Risen D-BT13/010 RRR

[AUTO]:When this unit is placed on (RC) or put on (GC), choose up to one grade 4 card from your hand, and reveal it. If you revealed a card, or your vanguard is grade 4, perform either of the following according to the circle this unit is on. ?(RC) - Choose two of your rear-guards, and they get "Boost" until end of turn. ?(GC) - This unit gets [Shield]+15000 until end of that battle. [AUTO]:When this card is discarded from hand while riding a grade 3 card from the ride deck or paying the cost for Stride, draw a card.