Naga Siren moves a lot. She is probably the most animated character in the game. (I don't know if you've played Dota 2 or not, a lot of people on this forum haven't) so keep that in mind when designing for her. The waist point is always moving in the idle animation.
I concepted a set for Naga Siren (not for the contest) and the modeller almost had a gun to his head trying to figure out the rig. If you're curious to see what we came up with click here
With all of that aside, H is by far the best one. And stick with the blues, don't touch the red ones you did earlier. Maintaining the characters color scheme is incredibly important.