There was a comic, Strike Force… something…
I read it when I was very young so it's foggy but it was the first story I ever read where the heroes died. They died a lot.
Aliens invade earth with advanced technology and the only way earth has to survive is to turn humans into biological weapons. They give their best soldiers super-powers but every time those powers are used they get closer to death. They all sign up for the program even knowing the powers will
I remember this one issue where a building had fallen and one of the heroes was using a force bubble to hold up the ruble and stop it from crushing the crowd of people he was protecting but the weight of the building was making him burn through his power quickly, the bubble kept shrinking as he grew closer and closer to death but a reporter in the group noticed a man-hole cover and the civilians pulled it up to crawl inside.
The reporter was the last one in and he called out to the hero who couldn't move and maintain the force field to escape, "What's your name?! At least tell me your name?!" and the hero said, "Today, my name is Bulwark. I stand defiant! Now, it's your turn. Go! Go tell the world they can stand to! We can fight back!"
Years later I thought back on that comic when I watched My Hero Academia and they had this scene - https://www.youtube.com/watch?v=Y7PlFZNnpdE