If you could save any of the characters in the hp books who died, who would you save and why?

Ah, this is such an interesting question!

Honestly, I think the most pointless death is Fred's, and if I could save him, I would. I could write essays on it, honestly. I think it's one of the cheapest emotional shots taken in the series.

Fred's death is kind of gratuitous. It's not well foregrounded, it's not a particularly good scene or a murder that's carried out by a character with any significance or symbolism (Rookwood? Really?) But neither is Fred's death used to be a particularly sophisticated comment on the randomness of death in war or make a broader point about the nature of the conflict at hand. It's as if the Weasley twins' position as a comedic device and a source of laughter throughout the series made them prime candidates for JKR to batter them, in order to hammer home an already hammered-home point that war is tragic and costly and terrible lol (like, already in the same book, George gets his ear blasted off! Why keep coming back for shots at the twins?)

You can almost imagine JKR going down the list of Weasleys like, ok, well Bill's already been mauled, killing Charlie wouldn't do enough damage because he's such a side character, Percy needs his redemption arc, killing Ron is a bridge too far and she's already had him poisoned, killing Ginny would be plot repetitive and would polish Harry off, she'd already decided to nearly kill then save Arthur, and Molly needs her boss bitch moment - oops sorry guess it's a twin that's getting it! Why not kill one and not the other for maximum devastation! It's not like JKR was even very attentive to the twins' emotional life or made any real effort to characterise the twins separately from one another, other than giving Fred more lines than George throughout the series. So for the reader, the death of one of the twins is this horrendous awful blow, but the reader also is left with no directed tools for how to think about his death or conceptualise what this character was for the series arc. Also to end a series knowing you just robbed this beloved family of a son and a brother - robbing George of his twin - and then make no attempt to think about the impact of that death on your characters, and write an epilogue that says all was well, is just extremely poor plot detonation, imo.

I say this also because I think there are deaths in the series that are awful and tragic, but which are still narratively and symbolically important, either as ways of propelling the plot forwards or offering a kind of narrative symbolism or arc that has some payoff for the reader. James and Lily have to die to set in motion this huge plot arc for the entire series. Cedric's death is a powerful watershed moment both for the reader - things are getting serious now - and for Harry. Sirius' death, while completing devastating, does at least make some sense to strip away from this central character an important protector as he steps towards a fate no-one can shield him from. Dumbledore's death was a masterstroke, and I actually (sorry) think Hedwig and Dobby's deaths make a ton of sense, as characters that represent innocence and the uncomplicated warm friendship of childhood friends (also I think Harry digging Dobby's grave is one of the most powerful images in the series). Even Remus and Tonks' deaths do something for the arc of the series, offering the symbolism of both another baby orphaned by war, and for Harry beginning the next chapter of his life as the godfather to that orphaned child (I'm typing that out very grudgingly because obviously those deaths are horrendous). But Fred, it's like, ok, well, the only possible point for this is to make sure you see it's a war and deaths will happen and to make sure the Weasleys are grieving for the rest of their lives. Great, cool, fine! But I think it's cheap storytelling. Anyway there's my piece!