*Pikachu uses Thunderbolt* *Null:* *AAAGHH!* Hehehe- Okay, okay! You know what? You are *really* going to regret that one. *AAAAAAAAAAAAHHHHHHHHHH!!!!!!!* *And so, it begins..!*
"Lets see, No Items, Your out of Power Po- (Glitching) aand It's your last pokémon, uh oh! Looks like you're gonna lose and there's liter- (Glitching) nothing you can do!"
I'm trying to think about how you would win the fight, since in the original, Null closed the 4th exit which should've been the win condition, meaning the only other way out would be to try and find a secret ending not using the traditional escape... which meant you had to start breaking the rules of the game yourself in order to win (Infinite sprint, increased speed, random throwable items in the halls that you hold like the numbered balloons) So maybe you'd somehow have to break Pokemon's rules like summoning all your Pokemon at once, ignoring the attack limitations of PP, attacking with the same pokemon several times in a single "turn", or even running away constantly and fighting in the overworld with your bike, even when not on cycling road. "Can't Escape! ... But you leave anyways!" Or you know, casually learn how to catch a Weedle from an old man, fly to another town, then surf alongside the beach on the eastern side. At least you'd have a fair fight, fighting a glitched, no-name trainer with a glitched, failsafe name pokemon. Of course, the missing number... MissingNo.
Theory: NULL not only appears in Baldis Basics but in every game that exists to mankind. I think that Null was a glitch created in the first vodeo game, Pong and he became sentient from there and started to expand across every game