The entire X-Men team sent to destroy the Sentinels primary base is killed, including the near immortal Wolverine. This was a very powerful moment in the Days of Future Past storyline. It showed that the X-Men dont always win. It would also serve as a powerful way for the X-Men: First Class timeline to permanently sever connections to the original trilogy timeline. Is there something else about the Days of Future Past storyline that you want to see in the film? Are there other X-men you want to see in the team, or another field leader?