Shane doesn't seem like an introvert to me. He's very independent, doesn't have many friends, but I don't think it means he's an introvert. He seems too naturally based in exploiting and changing the external world, he's fast minded and bold. There's no way to explore fictional characters on a complex level, so easy thought makes me think ENTP. It's easiest to say an INTP would be more likely to keep to themselves and ponder their idealistic views for the world rather than to try to make them become some part of reality, and I'm referencing specifically his speech he gave at his school graduation at a child.