I feel like Kamina is a great example whether you like him as a character or not.
The narrative sets him up not as a supporting character but as the clear deuteragonist. He is arguably the driving force behind the early part of the show, and the only reason you would ever really know Simon is the main character is because genre-savvy fans know that the core drill and Lagann will be important, and Simon will EVENTUALLY grow past his early timidness to become the real lead. But even then, the show sets up several moments to let you know that Kamina has an arc of his own ahead, that much of his bluster is a front and he will need to have the OPPOSITE arc Simon does (learning it's okay to be vulnerable and that you don't have to be the hero 100% of the time).
And then the show kills him with no warning Gurren gets taken out while fighting the first of the four generals, and you basically don't find out until after the whole battle is won that he actually died in the process. The show then does everything in its power to make that loss hurt, draining the color from the artstyle and leaving us with only a moody and supremely unlikable Simon for quite some time (until Nia comes along, literally bringing color back to the show as she brings positive energy back to the cast). And long after Kamina's death, the team is basically patterning their imagery and attitude all off of one man.
Kamina is easily one of the most impactful deaths in all of anime, and it makes no sense that he isn't in the top 10. Not behind fucking Mami and Kaworu.
i was shocked man, wasn't expecting that. Also Kamina's as well, thought he'd be the main character. Krillin's is probably the only one i agree with on that list, i wouldn't put lelouch on the list since in the same episode they hint that he's not dead.
