At that distance. Naughty probably goes stealthy. If he doesn't go with it at first, after the first blast, he definitely would. He is a smart bear, and would play the game smarter. He has fought a robot capable of one shotting him before, Knack isn't at that point if one shot, so I Believe Naughty can tank the hit if it does hit him before bolting off. Taking damage doesn't stop his movement. Even getting shot. I see him Getting out of site, getting around a corner or teleporting. Unless Knack ad a way to locate where Naughty is. Naughty is likely to get that Boo in he needs to make knack say screw this and run off. Naughty also could drive him insane if need be by simply wrecking the place. His presence and destruction has driven others to instanity and killing themself. Naughty isn't really bypassing that regen with most weapons. Debatably BFR could work, I don't see why not, but I wouldn't doubt there is reason it wouldn't. But that would require getting close. If he needed to get close though. A mega boo is all it takes when the guys in his line of site. Naughty counters his stealth with his senses and fourth wall awareness. The narrator telling Naughty typically where they are, if they are doing or fixing something, or if they get trapped in one of his traps. If it got into direct combat, well. Naughty still uses fear mid fight, so one boo would be all it takes to send him running. As well, if he pressure points. That can bypass the regen via basically destroying him down to ash. It works on even robots, so no reason it shouldn't work here. As well. He resists some of his element based attacks. So Stealth game, Naughty can Keep track of Knack, but not so much the other way. Stealth and teleport makes it difficult to keep track. A good Boo scares him off and naughty takes the victory there or drives him to instanity. Traps probably won't work to well due to the regen. In a direct physical fight. Naughty gets that boo in once and it scares him off. Mega boo leaves him stunned and ripped for a GG poke or BFR stab. Which at the guys regen, Naughty would resort to Very quickly. Naughty is undoubtedly skilled, even several robots designed to kill him by people who created a robot able to destroy the universe, he solos through several. Even beat one to death with a stick to prove a point.
Gonna day Naughty I think. But tell me if I'm missing something. I don't know this guy