In 6 panels you can give the basics of Superman.
Panel 1- The planet Krypton is ready to explode and no one believes kal-el's father, jor-El. So Jor-El-Builds a Spaceship to send baby Kal-el to Earth.
Panel 2- Krypton blows up and the ship crashes on Earth where Martha and jonathan Kent find baby Kal.
Panel 3- Teenager Clark Kent (formerly baby Kal) discovers he can run fast , lift heavy objects , and shit.
Panel 4- Clark realizes (somehow) he has to be hide his abilities from the world to keep his loved ones safe, and have a normal "human" life.
Panel 5- Clark decides to become a reporter where he meets the woman he loves...Lois Lane.
Panel 6- Here you can show how Superman's powers matured, or you could talk about Lex luthor....
That is all...you don't need to talk about kryptonite, Doomsday, Jimmy Olsen...nothing....the rest should be there as a mystery for the reader or a surprise...
Superman is an alien (the last of his kind---maybe depending on the year), Superman tries to be human by being Clark kent, Superman is amazingly powerful, superman loves Lois and fights Lex luthor, and Clark is a reporter.
Isn't that enough....?
