How to work with points in Chaos
Khorne is definitely not likely to win by points. He has the second longest dial, but he's the easiest one to do that. However, he can easily be shut out from that by Old World cards that restrict or outright eliminate combat. Then there's the Field of Ecstasy from Slaanesh. Khorne can only miss 2-3 times and has to last at least 5 rounds before he can win with that. He needs to have a backup plan.
Fortunately, he has one. He only has 4 cultists, but they can still add corruption. He kills off opposing figures easily, so he doesn't have to worry too much about being overtaken for domination. Still, he needs some backup. Enter the Skull Throne. Have your Bloodthirster in the Empire (already a good idea to scare away Teleport turn 1) with this thing, and you've already got 5 domination points. You only need one other thing there to take it for 5 points right away. Just use caution with this. It will negate the benefit of cultists for domination unless you have them upgraded. Unfortunately, this is your only chaos card that works to domination beyond killing things (or else card cost). You also have the Bloodthirster's upgrade making him count as 3 things, not that much different from the Skull Throne. With that, he alone can dominate most of the board, and he's big enough to stay around for a while. For the coup de grace, combine this with the Blood God's Call to make the Bloodthirster cheaper and have the 2 points from the card to take over whatever you need more.
Domination's definitely not all you need to do. Your dial is still important. It gives you a total of 8 points. You also need your cultists to add up corruption and ruin things, because that's where the real money is. Get your dial's 8 points (8th point awarded by 4th spin), eventually ruin the Empire (or any populous region made safe by lack of combat), and dominate regions for victory. By the way, let your opponents camp in the safe areas. They'll be useless once they ruin and they also mean more points for you as you ruin other things later. Don't forget to get some corruption in areas ready to ruin so that you at least get the Ruiners bonus.
* Your dial awards 6 points by spin 4 and totals 9 by spin 8. You probably won't get all 9, but the 6 is more realistic.You want to get some dial, but you don't need to rush it. You could rush round 1 and that's it.
* Dominate populous regions, but don't corrupt them too much. Ruining the Empire first gets you 10-13 points, which is already about 2 rounds of domination, anyway. Ruin later, dominate now.
* Don't be a wimp. Nurgle has about as much firepower as Khorne. Use it to defend yourself and keep your turf yours.
* Get Provender of Ruin when things look ready to pop.
You're definitely gonna have to be versatile to work this one. The most important thing for your point victory will be the Acolytes. They get to move Warpstones around while also corrupting regions, both contributing to ruination. Domination helps, but you really want things ruined. The dial doesn't help too much. You get the standard 3 VP by spin 3, but the other 5 will only show when you're one away from victory. Again, it comes down to fundamentally good gameplay for the character. Keep other people away from you altogether and you'll eventually prevail. Even if you get cornered, just Teleport yourself wherever you need to go.
Everything else will be based on how the other players are doing. Perverse Infiltration can get you some 2nd place points in an uncontested region, or at the very least help tip you over the edge. You've got as many cultists as Nurgle, so you have about as much power as he does to corrupt stuff without cards. If you can make a Field of Ecstasy, the two of you can be good buddies to ruin something. Don't count on your other figures doing much, though. Your Keeper of Secrets can be a nice boon when upgraded, but that should only apply really late in the game when you consider the Seductress upgrade is so, well, seductive.