First, you say you wait for the dragon to form before countering. That means the countless water bullets already pierced your body, that alone should leave you un-able to move, or atleast, bleed to death in 3-4 turns.
Second, the moment you reform underwater to use your mist technique, the sharks would long last already shread you to pieces, before you can even exhale/create the mist.
But who cares, let's continue. Just keep those in mind.
As the dragon hits you, we notice you are nowhere to be seen. Keeping a good eye around, the moment mist starts to hover out of the water, both brothers are aware that you are underwater. With that said, the 5 sharks rapidly surround you as they bite your flesh off and kill you mercyless to death.
While the sharks distract you and tear you apart. Nike focusses chakra into the bottom of his foot, creating a light green, hexagonal barrier that is fixed to the central area below the foot, said barrier remains invisible untill activated, wich happens when an outer force/attack makes contact with it. This is to secure the twin brothers from any technique you might want to launch at them from below.
Sora: We once met a hozuki..
Nike: He died.
At this same time, Sora uses wind based chakra and releases a gust of wind that forms several small tornadoes. The tornados form around their main body (Nike) and move outwards, thus, dispersing and blowing away most of the mist around them, successfully regaining atleast 90% of their vision.