https://www.polygon.com/2018/8/10/17675042/doom-eternal-gameplay-trailer-quakecon-2018-video-watch

During the opening keynote at QuakeCon 2018, Bethesda Softworks and id Software unveiled the first gameplay footage for Doom Eternal. The direct sequel to Doom, the series reboot that we named game of the year in 2016, adds several unique features not found in the 2016 game.

The most striking difference between Doom Eternal and past games? You can take control of a demon and sabotage another player’s campaign. Players will even be able to team up as demons to form a “slayer-hunting party.” It’s a mechanic similar to the one in the Souls games, where players can be summoned to another game as a Phantom — though instead of helping other players, you’ll be working against them in Doom Eternal.