It’s fair to say alongside a superheroes special powers or skills they’re mostly wrapped up in plot armour.
Nothing irreversibly bad can happen to them. They can’t die and they don’t take the brunt of anything generally harmful.
This is mostly the general rule for superhero comics, mainstream like DC or Marvel and creator owned properties like Invincible (from the writer who created the Walking Dead).
Looking at other genres like horror or bleak science fiction, the rules are different. Good people die, a happy ending is never guaranteed and someone you may like may die.
Crossovers between franchises aren’t new. It’s happened in cartoons with Jettsons and The Flintstones and G.I Joe and Transformers.
You probably don’t see many comic crossovers between different publishers it’s the legal nightmare which ensues for copyright issues.
A few which have happened DC vs. Marvel, Batman vs. Predator and Superman and the Terminator
The list goes on and there are more which have been buried and forgotten because of legal fears.
Whilst I was in a public library a while back I discovered something. Public libraries are a great source of graphic novels. They contain forgotten gems and save you a couple of pennies.
I found one of these said gems. Green lantern vs. Alien.
The story was published by DC and Dark horse comics (home to Hellboy, Buffy and Starwars) and pitted the Xenomorphs against the intergalactic green peacekeeping force.
The story sees Green Lantern Hal Jordan sparing the life of the aliens after he and team of fellow lanterns are sent to investigate the death of one of their own.
He claims the aliens are animals and can’t help there nature and places them on a planet out of harms way.
Ten years later after the Green Lantern corps is no more and last lantern Kyle Rayner and a team of former lanterns most go back to that planet and rescue a crashed ship.
Kyle must decide whether to maintain his non-lethal methods or wipe out the threat totally before it kills any more.
That little statement sums what’s so great about these crossovers. It’s about taking a hero that’s used to winning and living to see another day and killing of established characters, testing their moral codes.
In summary a great crossover is when a superhero must put aside that moral code and adapt to someone else’s world.