Adults are evil... Not true in the least bit, not in all cases. But Harry can sure as fuck understand how the kid would reach that point. Venturing into someone's soul does, after all, tend to breed understanding.
"Not sure if you can believe me, but I get it... Just a bit anyways, once upon a time I had a teacher in magic. He was, not very nice to begin with but it didn't start off too horrible."
Harry leads on, speaking slowly as he thinks back to days long past.
"His name was Justin DuMorne, and I killed him just to stay alive. He tried to take over my mind, succeeded in taking his other student's mind even..."
By this point they'd have been walking for a while, Harry still taking long pauses between words as he sees the faint signs of a town off in the distance.
"So I came back to save her or tried to anyways. In the end, I burned the dammed house down and my former teacher with it, so yeah I can empathize with the fact that horrible people have done horrible things to you."
A bit closer, and Harry looks back at them with a grim face. Staring into the boys once more, though thankfully a soul gaze only ever happens once with a single person.
"Even so? I can't believe that everyone is like that, for all the terrible things I've seen... I've also seen good men and women who'd risk their lives for nothing more than the slight chance to save someone else. I'm not nearly arrogant enough to call myself among that number, but I'll be dammed if I'm not gonna try to help anyway."
At that point, he'd go silent and twirl the staff around in his hands a bit. After a while longer, finally reaching the border of the town. With that, he'd set out to find... Someplace safe for these kids, with any luck it won't be impossible right?