"Oh good, I'm glad. You seem nice, I wouldn't want to fight you, but it's my job to if you're hurting people." Jack's family has ingrained in him the things that matter. He may have been on a much higher mission before he came here, but the important things are always underlined, like protecting people and stopping monsters (other than himself). He also can't be trusted to fight safely. He could blow up a building accidentally. It's better this way.

"I'm very bad at lying." Such an understatement. Jack also hates when other people lie but he almost never manages to catch them in it, because he trusts others bindly. At the question he nods, he can be asked. "I'm half-angel." From his experience most people know what an angel is, they're pretty famous creatures on his earth.