There is a line in a 1991 issue of the X-Factor comic book series where Professor X makes fun of the X-Men's inability to stay alive.

In subsequent years, it became more popular. In 2008's Final Crisis, Superman ends his eulogy by saying, "We'll all miss him." Pray for a resurrection. The Manhunter was back in action after the events of the Blackest Night storyline, which involved a god of death resurrecting dead characters. Batman has died. It's Spider-Man as well. All have been brought back to life. Death is rarely dealt with seriously in modern comic books.

Superhero movies have had this attitude towards mortality. At the end of Batman v Superman: Dawn of Justice, Superman died, but was resurrected a year later in Justice League. At the end of the movie, a lot of characters were wiped out, only to be resurrected in the film.

Iron Man, who sacrificed himself for the greater good when it counted, and Black Widow, who did the same without as big an audience, have the potential to come back, thanks to the endless possibilities of the multiverse.

Money or magic couldn't bring T'Challa back. Plans for a sequel to Black Panther featuring its title character were torn asunder after the death of actor Chadwick Boseman. Some people wanted the role to be changed and others wanted it to stay the same. What Boseman brought to the character was priceless. Putting a new actor in his place would feel like turning him into a different person. The work he did on Black Panther was crucial for that.

It was unavoidable for Boseman to be killed off-screen in order to make his death into a part of the canon. It allows the audience to channel their grief for the actor into their grief for the character, and it invites them to participate in the movie's own process of coming to terms with death.

No one is saying that a new actor will be cast in the future. Last month, it was announced that Harrison Ford would replace William Hurt in Captain America: New World Order. The studio wants death to be treated as an absolute. It creates an emotional depth to superhero stories that are hard to tell, and it treats T'Challa's passing with respect. It gives Boseman's Black Panther a legacy, rather than making him the same as the other heroes who have come before him.