Winter Assault/Titan of Khorne

This is a pretty easy level to do compared to the last two, mainly because you can turtle in the middle and build up your army before having to do anything. So what follows is just what I think is a fairly efficient way of doing it. Your first mission is to take control of 5 groups of imperial guardsmen with your psychic and lead them back to the sacrificial circle. You can do this at your leisure, so your first task is to fortify your base because you will get attacked from all directions at some point or another constantly for the whole time. So gun turrets all around, upgraded to missile turrets, is a good idea; including ones around your listening posts to the north east and north west. While you're there, upgrade all your listening posts to fortified ones too. At the same time build up your base and invest in a load of vehicles and a demon pit to get some obliterators on the job. I tended to leave a few units at the base to bolster the gun turrets defenses and keep repairing your gun turrets with builders.

You can then retrieve imperial guards from the three bases to the north west, south and east. However there is also a sub-mission of destroying the ammunition dump in the west that is pretty heavily defended and good to get rid of early on - so I started in the north west and worked my way round anti-clockwise. To get your psychic to control imperial guards, the psychic is tough enough on his own to get close enough to the bases, control the IG and walk back with them, but I tended to send a squad of chaos marines in as well to take away some of the fire and cover the retreating psychic as he heads back to base. Some bases you can capture two squads from and some only one. If you send more than just one squad of chaos marines in with the psychic you risk wiping out the imperial guard squad you are trying to capture. And although its tempting to stay at the base and let the imperial guards come to you, they generally have sergeants attached to them and hence can't be mind controlled and I found it impossible to just pick of the sergeant selectively; so its better to go and retrieve them from the bases. After you have stolen the imperial guard squads from each base you can level it and build listening posts. Once you've cleared one side of the board (e.g. the west), then you only get attacked from the other two sides.

Once you've brought 5 IG squads to the sacrificial circle, then the necron arrive and slowly creep towards your base. If your base is still strong you should have no problem defending it and sending out units to attack their bases. At the same time you have to go around possessing all the parts of the Titan with your sorcerer (who magically appears). This is pretty easy as he doesn't get bothered much and you just need to walk up to the flashing points on the map and click on "possess titan piece" in the options once the sorcerer is selected.

That's it I think! Happy hunting and congrats in advance on completing this campaign!