Not a superhero series, but there is a book called Old Mans war where the protagonists are elderly who get bioenhanced bodies to go fight a war against aliens.

Not a superhero series, but there is a book called Old Mans war where the protagonists are elderly who get bioenhanced bodies to go fight a war against aliens. If nothing else it was fun seeimg society that glamorized war but thought 18 year olds or even 40 year olds were mere children too young to choose to risk their lives.