Stream, Dragon Ruler of Droplets (BLMM-EN122) - Battles of Legend: Monster Mayhem 1st Edition

You can discard this card and 1 Dragon or WATER monster; Special Summon 1 "Tidal, Dragon Ruler of Waterfalls" from your Deck, but it cannot attack this turn. You can only use this effect of "Stream, Dragon Ruler of Droplets" once per turn.