Is it illegal to torture a home invader after you shoot him?

Lets just say that an unknown number of people broke into your house, but after you shot the first one, his friends fled. He's there in the hallway in front of your bedroom bleeding out, and you haven't called the police yet. You live in the middle of nowhere and the nearest neighbors are about a mile and a half away and there's some pretty thick forestation in between your respective homes. Even if you call the police, it'll take about a half hour for them to get out there. The guy has MS-13 tattoos all over him. Let's say you want to get the names of his friends. What's the legality of patching him up and then forcing him to hug a rusty oil drum filled up about halfway with hot barbecue charcoals until he gives you the names you want? Let's say that you live in Texas where the castle laws are VERY relaxed when this incident happens.