It's too bad this game will likely never come out, because I would have liked to experienced more of Original Sin II's characters.

The combat in the demo was more or less what you remember from Original Sin II, but fused into an XCOM like structure. You run tactical missions from a centralized base, often with a timed aspect so that you can't do everything. Seemed like there might have been permadeath. The story happens from a first person perspective when you return to base. Maybe had some sort of Persona-esque character/time management sim

They didn't have the balancing or flow nailed down when I played it.