Gallant Granite (Prismatic Secret Rare) [MP20-EN167-PrSR]

2 Level 4 monsters
You can detach 1 material from this card, then activate 1 of these effects;
• Add 1 Rock monster from your Deck to your hand.
• Special Summon 1 Rock monster from your hand in face-down Defense Position.
You can only use this effect of "Gallant Granite" once per turn.