This was a cool idea, generally well executed. I liked the idea of the leeches, and the leech runner who ships them from place to place. while the main character wasn't particularly likable, the situation was interesting enough to entirely make up for it.
The one thing that bothered me was the "twist" reveal in the middle. I like POV immersion. To me, that's what makes most stories worthwhile, sinking into a character's head. But when a character suddenly reveals a major secret that should've been clear from the beginning it throws me right out of the point of view to a far far distance. Instead of getting the "Oh wow" on the reveal like I really want in a twist, this sort of thing gives me a "Really...? That's really the way this is going to go?"
The tension of that scene is set up very well, setting up a seemingly unsolvable situation with the pirate in control of the ship and Titan locked in the cargo with the rest of the leeches. I was waiting to see what would happen, what kind of innovative solution he would come up with. And then the reveal--Oh, he can walk through walls effortlessly, though he doesn't like the feeling of it. And he's known this all along, in fact he escaped prison by doing this sort of thing. Speaking of leeches, that leeched the tension right out of the whole thing.
A POV character doesn't need to reveal to me every nitty gritty detail of their childhood or anything, but the fact that he's a leech, and a level 4 at that, is too important for it to be a reveal at a major moment within the story. Now, if Hemingway had been a leech or something, that would've been no problem, because he wasn't a POV character.