Video on Mortal Empires starting positions and objectives. Looks like the Chaos Invasion is still on, since ensuring Archaon the Everchosen is off the map shows up on everyone’s objectives.
Objectives generally seem to be
- Capture some leader-specific provinces. For example Mazdamundi needs to capture all the parts of Lustria that are on the Mortal Empires map. Malekith needs to capture all of Ulthuan.
- Build a bunch of leader specific high-level buildings.
- Capture or Military Alliance all other main faction capitals (e.g., Mazdamundi needs to have captured or allied with Altdorf, Karak Eight Peaks, Lothern, Oak of Ages, Skavenblight, etc.).
- As noted above, ensure that Archaon the Everchosen has been chased out of the mortal realms.
[Edit] There are a few factions with different objectives. Bretonnia factions just need to hit a certain amount of Chivalry and don’t care about anything else. Wood Elves just needs to upgrade their Oak of Ages. Chaos just needs to destroy Empire, Bretonnia and the Dwarves. Skaven are similar to standard billeted list above, but they don’t care about Archaon the Everchosen. In general the Old World faction objectives seem quite similar to their WH1 counterparts except in many cases the addition of needing to be allied with or control main capitals.
I wasn’t taking very careful notes, but IIRC factions that need full control or alliance with all 17 major capitals are: Empire, High Elves, Dark Elves, Dwarves, Greenskins, Lizardmen, Skaven, and Vampire Counts.
Video is by Party Elite who did the outstanding beginner’s guide to Total War Warhammer video series — highly recommended to anyone still learning the game.