Looks to me that he’s damaged/severed the blood supply and nerves to that toe from whatever he cut it on, which is why it’s kind of dry and funny looking. It will probably slough (fall off) and yeah, the biggest thing will be to keep it clean and dry, and monitor for infection. Similar to frostbite, really. The tissue becomes devitalized, dies and falls off. Since he’s getting around well and doesn’t seem too bothered by it, I would think he’ll do fine. I wouldn’t go too crazy with putting various ointments or treatments on it though, sometimes you actually trap bacteria in there and cause more harm than good. It’s also easier to see if it’s beginning to have any discharge or color changes if there isn’t a ton of other things on it. (Is it dried ointment, or pus?) I would also try to keep him out of bath water, etc until it decides where it’s going to let go from. That’s my 2 cents, lol, based on cases we’ve seen at the clinic. of course, nothing any of us say on here will be as good as having a vet actually see him. There’s a reason nobody will diagnose based on pictures alone. good luck with him! He sure is a cutie.