I started to think of comic book heroes, and began an alphabetical list of DC superheroes. No villains. No Marvel. And no Legion of Super Heroes! (I've had to expel most of them from the memory banks over the years anyway; they really are legion.)
Tough challenge? Surprisingly. At D I hit my first snag, having to resort to Deadman. And I had thought I could coast just using Justice League members for a while.
But at I, I was totally stopped. No I heroes? It would seem not; having dissed the Legion I couldn't use Invisible Kid. No Marvel, so no Iron Man. I finally had to give up.
In the morning, a check of the DC Comics character database (which, admittedly, is far from exhaustive) showed no I heroes.
This seemed to show a dearth of imagination. I figured I'd come up with an I hero for DC, which they might choose to use in any way they like, so that I could complete my alphabet.
I couldn't come up with a name for the guy---well, beyond the first letter, anyway:
You think about it, DC, and get back to me. Hey, if the character sucks, maybe people will pick on him and leave Aquaman alone for a while. Win-win.
P.S.: I mentioned my I dilemma to the highly intelligent Mrs. Key, who immediately said, "Isis." Isis was indeed a DC character back in the '70s, concurrent with the Saturday morning live-action show that ran for two years. Filmation did the series, and I'm not sure that they didn't own the character. Nevertheless, the comic book ran eight issues, and the character has appeared since, in altered form. I think I would have been reluctant to use Isis as the I---not because of the terrorist army that has used that name, but because of her peculiar history in the DC universe. Still, my wife beat me at my own game, and she's a total non-dork, so big props on that.