-Before Gurren Lagann came out Shinji was a wimp…
-After it came out…

@Kung Fu Cthulhu Many fans of TTGL know that Kamina wasn't the true badass of the series, that was reserved for Simon; what I like about him though- and what sets him apart from Shinji- is what he stood for and tried to emulate, hope and the will to move forward. Kamina knew he lacked the inner strength to achieve his goals, but he knew Simon did; and thats why he acted the way he did, to lay down the foundation for Simon to truly "Believe in the you that believes in yourself." as he told him while dying. Shinji on the other hand had no such thing, and as a result spent the series growing more and more depressed as his inner strength dwindled; wich left us with a suicidal, self loathing, socially isolated, teen who really was not someone to emulate of aspire to. All in all, my opinion: Kamina= Hope, Will, and the desire to achieve ; Shinji= Depression, Self loathing, and giving up.