It's engrained into him, nothing else matters, protecting Harry at all costs is what pumps his heart and floods his veins. It's just, he didn't count on the one thing Harry would need protecting from would be himself. (Harry and Louis are in love, and they are probably soul mates. They just can't be bond mates because despite the undeniable pull, it's them against the world.) I did not write this. All credits go to itiswhatitisbutterfly on ao3.