There's bound to be some major deaths either in <em>Avengers: Doomsday</em>, <em>Avengers: Secret Wars</em>, or both. Thor and/or Hulk seem like good bets, though I also wouldn't be surprised if one or two Thunderbolts/New Avengers kicked the bucket as well. That said, it'd certainly be a major twist if one of The Fantastic Four meets their end at the hands of Doctor Doom, especially as they'll have just been introduced in 2025's <em>First Steps</em>.