^You would kill off three of the show's most popular and most important characters. This show has its roots very much in comic books, it is extremely rare for major characters to permanently die.
Killing off Peter, Nathan and Sylar in the same episode would be like killing off Spider-Man, Iron Man and Doctor Octopus in the same issue. Never going to happen.
:sighs:
So very wrong.
First, neither Nathan, nor Peter are very important. Peter is too powerful, he would bitch slap anyone if he used his powers correctly. Thus, a story where Peter is allowed to be smart and use his powers, would have no drama, because all problems would be solved by him single handedly in a single episode. The other possibility as we've seen the writers take; is make Peter stupid, and look at the complaints about that one. In short, Peter is not a story-making character, he's a story-DESTROYING character. Which means, he is NOT important to the ongoing story. His story ended at the S1 finale, and only that arc he was important to, and even that's debateable. He really, was that story's MacGuffin, the one that would go boom at the end.
Nathan is even LESS important. He doesn't do anything. He hasn't done anything in S1, he hasn't done anything in S2, and he's done even less during S3 so far. He's a glorified side-character. He was only reasonably important, or rather useful in S1, because he was the brother of the one that go boom, and he was stuck in a political intrigue. His story was simply: whether he'd be a villain that chose power, or be a hero - and sacrifice his life in the process, by getting his brother up into the sky of New York. He's a character that's only coasted along, being dragged along by the actual protagonists and thus the important characters of the story.
Sylar is a villain. A villain is never important to a story. Any other villain can fulfill the same role. A villain is only important to a character, and only rarely important enough to keep around for very long. Sylar, as such, was important to Hiro. Hiro went on the quest to save the world, and the only way to do that, was to kill Sylar. So Sylar's role, his only importance, was to fall to Hiro's sword. The moment he survived it, his importance was gone, completely. He did not fulfill his role, so he became unimportant. Which you can see, S2, he was de-powered and spent his time traveling with the wonder twins trying to get his powers back. In short; not important, in any way shape or form. S3, is WORSE. Not only doesn't he have anything to contribute to the story, he is SO UNimportant to the story, that he's effectively been destroyed and killed, now he's just Booboo.
Also, as for comics. I'm a comics fan, but I know there are a lot of bad things, specifically habits in comics. Things that make people consider them juvenile. Some of those things, that some comics, try to avoid. And bringing people back from the dead, or letting them miraculously survive things they shouldn't have, prolonging their existence, is EXACTLY one of those bad things. And as a tv show, they should have used the good things from comics, and AVOID the bad things. Yet they didn't, they not only kept the bad things, it seems they went ahead and made just about their entire show nothing but the bad things. Is there even ANY threat of death to ANY character? Dead? Oh, just bring a bit of Claire's blood, and away we go. Seriously, Noah surviving a bullet to the brain with a bit of Claire's blood (which makes you wonder why Peter isn't getting up) is just seriously bad. Any hope that this Season would drag this show out of the bad, but instead it only got worse.