[Xabre]

I'm a big fan of Champions of Fenris mostly for allies. With the fact that you don't need troops, it's a great way to drop in some allied Dreadnoughts (cheaper than Grey Knights), not to mention with access to 4 HQ, you can throw in a bunch of Rune Priests... lots of great combinations.

The Voidclaw formation is also really sweet to add some reserve control.