Ok, seems like a video submission is a little too much for just something like this. Well heres the hero i came up with:

Water Cannon:
Model - Hydra
Attachments:
origin: The crazy blue and yellow immolation thing
Left and Right Feet - Drain
Left and Right Hands - The spinning blue missile effect, basically anything blue that leaves a trial behind it.

Concept:
My hero is intended to be like a living water gun, he draws water up from the ground and the atmosphere around him.

He would have an ability which would store water in him every second, this would be his base ability. The more water he stores, the more damage he will deal with his other abilities. Each time you increase this abilities level, the max water is increased.
His other abilities would use this ability, like one would be a knock back cannon, and the other would be a wave cannon that would shoot more projectiles into the target area depending on his water stored.
His ult would cause the area around him to flood and pillars of water to shoot up and toss enemies into the air and dealing damage when they fall.

(Enlarge the pic for a better look)