When I was a kid there was this Marvel comic where they battled some robot aliens and most Marvel superheroes died, the first superhero to die was Spider-Man, Death's Head was there and they said that only way to save the Marvel Universe was to find a way to resurrect Professor X.

Alien robot species had laser guns that could shot everyone, the only one they were having trouble shooting down was Colossus because of his titanium body.

It was a very awesome issue of Marvel Comics and I couldn't remember what it was, hoping somebody could help me and know what I'm talking about.