Blue Storm Dragon, Maelstrom
[AUTO][Limit-Break 4]:[Counter-Blast 1] When an <Aqua Force> rides this unit, you may pay the cost. If you do, choose up to one of your vanguards, until end of turn, it gets [Power] +10000, and "[AUTO](VC)Wave-4th time or more (This ability is active during the specified battles of each turn):When this unit attacks a vanguard, draw a card, choose one of your opponent's rear-guards, retire it, and until end of that battle, your opponent cannot call grade 0 cards from hand to (GC).".
[AUTO](VC)Wave-3rd time or more (This ability is active during the specified battles of each turn):When this unit's attack hits a vanguard, search your deck for up to one card with "Maelstrom" in its card name, reveal it to your opponent, put it into your hand, and shuffle your deck.
Maelstrom. A blue dragon among blue dragons.