Relic weapons: I’m each act their will be a relic weapon. We don’t know what they are but some examples would be The Gorgon, Hammer of Dawn, Breechsot ect.
Hack and control swarm: You can hack the Hunter, warden and puncer. potentially more.
Jack is extensive: Jack has several abilities and can execute enemies.
In Act 4 someone will die horribly.
Seems we may get a cliffhanger: “Discvovered the true threat to Sera” complete the game.
Their will be nameless friendly Jack can revive. Most likely COG gears, as seen in the 2018 trailer.