Well, Its either Skull Gir/ Molly or Hydromancer, ebing the two most "visible" main charecters in the story, and I know when I sketch out a concept in my head, the original protaganist usually doesn't change (beyond maybe his/her name) when I start writing my story. My vote just goes for Hydromancer becuase he's an actual "Hero", and thats the classical, colloquial meaning of "protagonist"
"Justice is the Art of the Thief"
"Weapons and armor are for those who lack skill, Honor and courage"
~Drunken Monk to a Paladin in the tavern. No bystanders were harmed in the ensuing brawl~