I've been trying to think of foolproof ways to kill characters in a way that nobody could really undo. Uncle Ben, unlike Pa Kent, can't come back because his death is the engine for Spider-man's existence.
People talk about the great cancer story (yawn) that constituted the death Capitan Mar-vell. I missed that ish somehow and would really like the treacherous Kree back where he belongs, which is basically Steve Rogers with the Sentry's powers. Hell, has Disney realized they own a Captain Marvel?
It's tradition for each departing Daredevil writer to write his successor right into an unsolvable corner.
MY garbled OP is how could you dispose of a character that some comics guy would have a hell of a time bringing back to life. And no voodoo or magic.