Ryu uses this sroll to call upon thunder from sky using the nessicery hand signs and his chakra. To use it Ryu first pull out the scroll from his pouch(or werever) and performs the hand seals. Then he lays it on the ground and taps his foot in the middle of the scroll. Then thunder clouds will form over a large area so they can inhance some of Ryu's Lightning Release Jutsu's.