> I don't remember a comic book where he really went all-out-to kill without any hesitation or fearing that he is afraid that he will hurt innocents.
> As far as I know,he went all-out only against Doomsday.
> But since I probably missed some of the issues,I can't tell for sure.
> Does anyone know this?
> Big thanks!
When Superman went "all out" during Our Worlds at War, he went from BARELY being able to survive a single Imperiex Probe to tearing through a whole army of them with ease. When he fought Earth 2 Superman during the Superman issue of Infinite Crisis, the power he and E2 unleashed damaged space and time and destroyed Earth 2 completely (it was restored by untold means later). They didn't even hit the planet -- just themselves, destroying the planet in one final shot and causing the universe to go all whacky. He and Phantom Zone Zod also destroyed a planet (during Lee's run), incidentally, just by pounding on each other (each hit on them was transfered onto the planet, or something like that).
Incidentally, these are all feats that NO ONE ever talks about on the Battle Board or Marvel-centric boards. Sure, fans will overhype the significance of Hulk holding together two tectonic plates [Somehow, that becomes "Hulk pulled a planet back together" -- what? How's that work?] ... but Superman destroying a planet (twice in one year, no less) or messing up space-time? Those things get ignored. Hulk performs one big feat in, I don't know, 20 years and it's taken as a true representation of his strength, rather than a statistical anomaly. Superman holds a black hole in his hands; helps tow Earth; splits a small moon in one hit; absorbs an explosion powerful enough to "destroy half a galaxy," does better against SBP than an assemblage of GLs, Black Adam, J'onzz, etc.; forms a key from the core of a star, etc. -- all in the last 5 years or so -- and what do you get? Facile dismissals and charges of "unrealistic," "jobber," and just flat-out "WRONG!"
On a different note: Superman didn't cut loose completely against Doomsday -- he only thought he did, as Mongul explained and proved to him at the start of Loeb's run in 1999. Given his insurmountable conscious and unconscious restraints on his power, we probably have never seen Superman cut loose 100%. I doubt anyone but he himself could access that level of power, which, I'm guessing, will always remain unknown.
Jeph Loeb, Jim Lee, Brian Azzazello, Joe Casey, Joe Kelly, Mark Verheiden, Chuck Austen, etc., have all written Superman as having an incredibly dynamic level of power. Like Jeph Loeb said about Superman smashing Wonder Woman's bracelets in Superman/Batman (paraphrased) ... piss off Superman and there's nothing made by god or man that can withstand his power.
Of course ... other writers will disagree, I'm sure. But, then again, I'm stupid enough to think that, on average, Superman could fart Mjolnir in half ... so, until that average shifts in some major way, I could care less.