The key word in what I had said was fast. As <3 said, Midna can easily have her own moveset. She doesn't need to use the giant hand for anything but tilts or grabs if she wants, she can have a jab similar to M2s (but with less suck) and have magical attacks for all of her B moves.
Magical attacks for B moves is a must, and these would all be centered around Midna (seeing as Link doesn't have magic in TP, unless you count Magic Armour), but what's the harm in giving Midna faster movement and more staying power (weight), as well as a larger variety of A moves by putting her on Link? I think having both of them results in a more original, better moveset. Better meaning higher-tier-better.
Here's the best moveset I can come up with, but I'm not a well-payed Japanese game developer...
A: Bite : Wolf link bites. Tapping A several times causes you to do successive attacks.
> Tilt : Midna uses her hand (on her head) to slap opponent.
> Smash: Wolf Link leaps forward and headbutts opponent
^ Tilt : Wolf Link rears his head upwards (headbutt)
^ Smash : Midna swings her hand from front to top, hit all foes in its path.
\/ Tilt : Midna's hand swings around the front of Wolf Link and on the ground, hitting foes infront of and at Link.
\/Smash: Wolf Link does a spin attack sending all foes outwards with his tail. Hit's back first.
^ B : Midna and Link warp to whatever direction you tilt as black fragments of shadow magic. These hurt foes caught in their path. (Midna stays solid and hit-able, but is more-or-less defended by Link's particles. Obviously, if Midna gets hit or die, Link turns solid again and suffers the same fate).
> B : Midna creates a dark-magic projectile (Like the one she uses to break Wolf Link's shackles in your first Twilight encounter.
B : ??? Can't think of anything cool enough for a neutral B right now. It'll come to me later.
\/ B : Midna expands Links energy field (B attack in TP). An orange circle expands on the ground. Enemies that touch it are frozen temporarily. When \/B is released, Wolf Link attempts to attack each opponent in the order that they were frozen. Opponents are unfrozen a moment after he begins to attack (the first snared opponent always gets nailed, but subsequent opponents have a chance to escape or shield). If no opponents are snared, Link does an ineffective and time-costing spin attack. Opponents can free themselves the same way you get free from a grab. The move has a maximum duration of 5 seconds.
Dash Attack : Wolf Link charges into opponent while Midna swipes hand. If hit in a lower, small hitbox (new crouching opponents), Wolf Link hit's them at a low trajectory. Otherwise, Midna's hand nails them upwards and forward.
Grab : Link bites onto opponent.
Grab Hit : Link bites opponent while still holding on.
Forward Throw : Midna grabs (using hand on head) opponent from Link and tosses him/her forward.
Back Throw : Link, while holding opponent in mouth, spins and throws opponent backward.
^Throw : Link backflips, hitting opponent upward with his tail.
\/Throw : Midna grabs opponent from Link and pounds him/her against the ground.
Neutral Air : Midna flips around Wolf Link's head and they both spin. Front gets kicked by Midna, back gets tail lashed by Link.
Forward Air : Wolf Link headbutt's opponent forward.
Back Air : Midna holds onto Wolf Link and kicks behind her.
Down Air : Both characters flip forward, Midna's hand slams foes downwards (Spike).
Up Air : Both characters flip backward. Wolf Link tail lashes enemies upwards.
Super : ??? There are a lot of possibilities for this. Midna could make the entire stage disappear if she wanted.