Princess Diana
Amazon

While this guy is very new (his game's not even out yet @__@;; ) i think he'd be a very interesting character to play as. There is the problem that he is from konami like snake but there was never a limit to how many characters one third party can have. Besides he'd be NOTHING like snake anyways.
Anywho, Dewy would be able to change forms based on his temperature which would make him very unique. Since his game is yet to be released there isn't much information on what he can do but some of it includes freezing himself and turning into a cloud.
Well here is a possibility for his b moves:
B: Slide: This attack is chargeable, Dewy stands in one place and water forms around him that pushes anyone away from him. After you let go of the B button Dewey jumps forward and slides in one direction with water all around him, sort of like piplup. Once you hit someone dewey flies back a little and lands. You can turn while sliding but it will decrease your momentum.
B-> : Gust: In Dewy's adventure your able to manipulate the world that he's in, one of the ways you can do this is by making a fanning motion with your wii mote which causes the wind to blow. Dewy will spin around while anyone who gets near him is blown back, this move doesn't deal damage but gives alot of knock back like mario's F.L.U.D.D. While doing this move Dewy gets blown foward just a bit.
B ^ : Reform: Dewy breaks up into water droplets and they fly upwards to regroup themselves back into Dewy. This has very long range but a bit of start up lag and it does no damage.
B v : Temperature: This can change Dewy into either his ice form or his cloud form and maybe others that haven't been revealed yet. Anyway this move is random so you don't know what your going to transform into. While transformed your b move changes
Ice Form:
If you turn into your ice form Dewy freezes and if he was on the ground while preforming it a small area of the ground freezes over. The ground stays frozen for a few seconds and it will be slippery. While in Ice Mode Dewy will be much heavier and much more powerful. However he will have very low traction and decreased jumping abilities. While dewy preforms his gust move he will not move during it, Also Dewy's recovery move will break him up into icicles which shoot forward, doing damage to anyone who gets hit by them, and then reform into Dewy although the distance recovered will be less.
In this form dewy's b move turns into a spinning move, where Dewy spins rapidly and then jets out at an insane speed, this move deals great damage and knockback, but if you don't hit anything you'll perish because you can't stop this move.

Cloud Form:
If you turn into your Cloud form dewy will boil and then turn into a cloud of vapor. Once Dewy transforms into his Cloud form he shoots out a bolt of lightning downward, if it hits the ground it will electrify it for a few seconds and anyone who steps on it gets stunned. In Cloud form dewy is about as light as jigglypuff. He is much faster in this form and hovers a bit above the ground, he does fall like anyone else though. Dewy's jumping abilities are worse in this form but he has multiple jumps like kirby and jigglypuff. If he footstools someone they get struck by lightning but its no different from anyone else's just that it gives a cool effect. Also his reform move changes into Dewy leaping out of his cloud forward and his cloud reforming under him with the move ends. It would be a bit less than his normal form but if dewy crashes into you while he jumps forward you receive fire damage and are propelled backwards.
Dewy's b move changes into an electrical move while he's a cloud. He jumps out of his cloud and it shoots electricity to someone within its range. This move deals pretty pathetic damage, about 2%, but it stuns anyone who got hit by it! This move is chargeable and if you charge it a giant bolt of electricity hits Dewy and he gets 10% damage added to him, although it will create a giant explosion like Roy's b move that will do tremendous damage and knockback to anyone near him. A good strategy would be to use the uncharged version of this move and then try to hit them with the charged version.

Final Smash: Poseidon's Fury
If Dewy grabs a final smash form no matter what form he's in he will go back into his regular form. The bottom of the stage gets covered in water and then dewy jumps backward into the background and splashes into the water. Then pillars of water burst out of the stage and throw people high into the air. After about three water pillars a blast of water shoots out from one side of the stage that will throw anyone caught in it out of the stage. Then the water drains and dewy slams down onto the stage dealing a bit of damage and little knockback. These pillars and blasts of water are somewhat thin so don't worry about it being a bit broken or something.
Note: if the stage moves in anyway, while this final smash is preformed it stops moving.
Anyway, Dewy for brawl!