Time Traveler's / Reincarnator's 'Hitler' Dilemma

[Kiradien]

It's been long asked: If you could travel back in time, would you kill baby Hitler?

For a multitude of reasons, the answer usually ends up no, but reading a Star Wars fanfic left me wondering, how many story plots would effectively solve themselves or would at least be better if you offed the protagonist before it started?

If you reincarnated before the plot of the story, are there protagonists you would consider killing off for "the greater good"?

What stories and what characters would make you consider doing so?

 

[Kiradien]

I would consider killing off these protagonists.

Star Wars - Anakin Skywalker
Darth Vader is iconic, he is THE bad guy in movie history... He does an enormous amount of harm, he kills the younglings, he's quite literally evil... He's evil, it'd save trillions of lives, Sideous' plans would struggle without someone positioned like him... But I don't think I'd actually be able to kill him as a kid.

High School DxD - Issei Hyoudou
Issei is an irredeemable pervert, but he's also the source of all problems in DxD. His breast obsession opened a gateway to the breast god of another reality - a gateway that the Chaos Brigade noticed and researched. It could be argued that the Chaos Brigade only grew in activity *because* of Issei, but it's a fact that the ExE plotline falls squarely on his shoulders. Yeah. I'd definitely kill Issei.

Warcraft 3 - Arthas Menethil
The Patricidal Lich King, slayer of kingdoms and spreader of undeath. All around bad guy. I'd probably consider trying, but considering he's a prince raised into a powerful Paladin, I don't like my odds.