Originally Posted by
Primetime Harder
If Harry is specifically told that the Laws don't apply to him here...yeesh. Watch out, bad guys.
He'd probably get to the bottom of that whole Baratheon-bloodline morass fairly quickly through use of thamaturgy, and go about setting Gendry on the Iron Throne. Then he'd either negotiate a truce with Danaerys, or if that didn't work, blast her dragons to smithereens before they could become a region-destabilizing threat. I'm not quite sure what he'd do about the White Walkers, but his power as Winter Knight should be sufficient to do something - maybe even control them outright and tell them to back off.
Also, it is 100% guaranteed that at some point, someone will hear, "Alright, you primitive screwheads, listen up! THIS is my BOOMSTICK!"