Here's a summary of the Dice Tower video that I posted in that other thread for those that don't want to go digging through it:
First they showed off the enemy models and some of the tiles for the Derelict Ship. They mentioned that hull breaches can occur and pull Heroes down a hallway, or there might be a gravity malfunction and they have to pull themselves along the walls. They also mentioned three artifacts: an energy blaster, gravity boots and a space suit.
Then they talked a little about the Feral Vampire mission pack. They showed the objective room and said that one side is the vampire nest and the other side is a "lost tomb" on some other world. When a Hero gets Bitten by a vampire they slowly become one. The Hero gets stronger and faster as they turn but they rapidly go insane. They also can't visit Churches or use Holy items.
Next they looked at the Hellfire Succubi. The map tile was a Cynder Summoning Room on one side and a Cynder Throne Room on the other. The Succubi were described as being "one of the most vicious enemies we've introduced to the game, yet." They mentioned the Femme Fatale ability and zooming in on the text on some of the photos on Twitter/FB, it looks like male Heroes can't get crits against them and the Succubi are +1 Combat against female Heroes. It also looks like Heroes are -1 Defense against Succubus attacks due to their "Vicious Claws" ability.
Each mission pack will come with an Adventure Card which is a small card that is played in addition to a regular mission (such as a mission from the core set, for example) to give it more of that mission pack's theme. So if enemies are spawned there is a greater chance that they will be the mission pack enemy (or that they'll show up in addition to any other Threat cards, it wasn't clear), and if there is an encounter there's a chance that there will be an additional mission pack-themed encounter. The special encounters are also small cards and I counted 12 of them in the Succubi encounter deck.
More powerful Succubi, like the Hellfire Witch, can cast Shadow Majik spells. It looked like there were 5 cards in the spell deck and the card backs are identical to Beli'al's Shadow Majik spell deck. Since that's the case, one intriguing possibility is that the Hellfire Witch will be able to cast any Shadow Majik spell, including one of Beli'al's.
When you encounter different mission pack enemies there is a chance they will have a specific Trait, which is a card from a small deck that gives them different behaviors or buffs/debuffs. The Succubi have Traits like Charred, Pit Dwellers, Bel'ian Coven and Magma Kiss, and it looked like there were 5 cards in total. The Feral Vampires have a Trait called Light Sensitive: the vampires have a lower defense when close to the Lantern Bearer but then they prioritize targeting them.
Finally, they showed off the Ancient One model but didn't discuss any of its mechanics or abilities.
And here are the release dates they gave:
May: Derelict Ship
July: Flesh Stalker & Drones, Ally Pack
September: Burrower, Scourge Rats
October: Feral Vampires, Undead Gunslinger
December: Beli'al, Hellfire Succubi
2018: Ancient One