I can't believe I'm saying this but I say Spongebob, while Mysterio did end up causing the events of No Way Home, he had no idea what would happen due to his death (even though he probably wouldn't care as long as it meant he could be seen as a hero by the public), Spongebob on the other hand not only caused countless deaths and made his own best friend turn into a horrific monster, but if we take the vision Sandy had of killing him into account, then he would've likely killed the entire town if they found out who he truly is.

@MarkyBoy51 It's funny cause I randomly picked both of these PE's, but they both are pretty similar in their methods. Both of them painted themselves as good guys and acted like they saved the day, but in reality they are actually heartless sociopaths that could care less about the people they got killed. They had a reputation they wanted to keep and they were willing to kill anything and anyone to keep that reputation at hold. They had different goals but similar methods. Spongebob wanted to get Mr. Krabs and Plankton killed in the massacre in order to open up his own restaurant without competition, while Mysterio wanted to be the next Iron Man without actually doing anything heroic. Both of them ignored the severe amount of civilian casualties. The only difference here is the fact that Spongebob won and Mysterio lost.