i doubt how possible it is legit but you can easily edit your save files to give yourself a sword that does insane damage and change your hp to hundreds of thousands.
Well, then of course there's nothing in place for if you win. You can't win that fight, unless you modify the game. At that point, the devs aren't able to consider what you're doing. That's why you get a black screen, you beat an enemy that was specifically designed to not be a win condition. It's a game over.
Because it's not a fight that you win. You instantly get killed, because you're trying to fight a giant. That's a joke situation, not something you're even able to get past the first round of. If you trigger an outcome that's not possible at all, then why would they put anything there at all?
