
Gabbing Geek, like any online publication worth its salt, has editorial discussions. Watson was wondering how a story on longest-dead characters would go, specifically ones that stayed dead or had actual emotional impacts on the reader, especially if they died during an “event”.
Shortest death: probably Hal Jordan as Paralax in Zero Hour…back the very next month in the pages of Green Lantern. Longest may be Captain Mar-Vel, still dead and staying that way.
But that idea sounds like it would require too much research, so instead I’m gonna talk about Supergirl.
Supergirl belongs in a strange subcategory of superheroes, namely the female version of the established male hero. Not quite the kid sidekick, and maybe popular enough to get her own series, the better ones get developed enough to more distinctive characters, or even adopt new hero names or identities later.

Supergirl may be one of the first, after Mary Marvel of the Marvel Family, and her history is probably only second to Hawkman for outright screwiness.
Actually, Mary Marvel has one other thing in common with Supergirl, namely a creator. Writer Otto Binder created both characters, as well as female Captain America knock-off Miss America.
In 1959, Superman discovered, not for the first time and probably not for the last time, that he was not the sole survivor of the Planet Krypton when a rocket dumped his teenage cousin Kara in his lap.

Now, comics thrive on coincidence. Peter Parker doesn’t stop a common thief, and that same thief goes all the way across town to kill his beloved uncle, because any other random house would have led to a very different Spider-Man, I am sure. But somehow, destroying a whole planet and making sure there were only two survivors (plus a dog, a shrunken city in a bottle, random bad guys in the Phantom Zone, etc) just so happened to be first cousins always seemed a bit much for me. I mean, I know why it was done, namely to prevent fans from demanding Superman and Supergirl repopulate the Kryptonian race, even if a grown man romancing a teenage girl wasn’t squicky enough.

So, what is a Superman to do when his teenage cousin suddenly appears out of a rocket? Simple. Stick her in an orphanage and keep her existence a secret.
Good parenting is what the Silver Age was all about. So are good relationships. One “imaginary story” had Supergirl marry Jimmy Olsen…without telling him she was Supergirl. Oh, and standards meant separate beds for them. Jimmy sharing a bed with his own wife? Unheard of.

Supergirl did have her share of problems. Comet the Superhorse was in love with her.
Maybe she should have stuck to her cousin.
Supergirl’s adventures would continue, but despite her initial popularity keeping her around, she did have a more popular rival.

Yes, Power Girl, whose own history is convoluted enough, was the Earth-2 version of Supergirl. She was the cousin of Superman from Earth-2, had all his powers, and so forth. When The Crisis on Infinite Earths rolled around, one of the unstated “rules” for cleaning up the multiverse was that if two identical characters from different Earths existed, then one had to go. Usually it was the more popular of the two, so characters like Lex Luthor and Green Arrow of Earth-2 bite the big one. But here were two Supergirls, so, who gets to stay?

Yes, despite the rockin’ headband, Supergirl died. Power Girl lived. Even the movie with Helen Slater couldn’t keep her alive.
Then she came back. Sort of.
John Byrne had rebooted Superman back to scratch, and with the reboot did come a Supergirl, known also as “Matrix,” a genetic blob of artificial protoplasm from a pocket-universe created by a good Lex Luthor. This Supergirl could change shape, and her powers were similar to Superman’s, but she also had some telekinesis and really good invisibility. More like J’onn J’onzz than Kal-El actually…
This Supergirl would get her own solo series written by Peter David, having her merge with small town bad girl Linda Danvers of Leeburg (taken from the original Supergirl’s secret identity of Linda Lee). This selfless act for a dying girl nearly beyond redemption led to Supergirl becoming an “Earth-born angel” complete with nifty flaming wings and such.

She even eventually changed her look to match the Bruce Timm version that appeared in Superman The Animated Series.

Then Jeph Loeb, who never met a Silver Age concept he didn’t like, brought back the Superman’s cousin angle, in an especially creepy series where she traveled to Earth naked, and Lex Luthor would comment on her boob size.

And through it all, Power Girl never really went away.
So, to recap, cousin-blob-angel-cousin again. Arguably the “classic” Supergirl died in the original Crisis and stayed dead until the cousin angle returned. Many takes on her now seem to focus on making her some kind of bad girl, and not just with the bare midriff. She’s more likely to be rougher, or possessed by Darkseid, or something along those lines.
Except she’ll be on CBS soon, in some kind of crime procedural, probably because that’s the only kind of hour long drama CBS knows how to make anymore.
I wish I could get into this – I really do… but I’m still on the fence.