They are tough even by Space Marine standards and have access to some super-powered heroes and specialized equipment. They are particularly effective against daemon armies, but don't think that limits their effectiveness against other foes.
There is currently no Battleforce Box, but this will get you started:
Grey Knight Terminators(5 models)
Grey Knights (5 models)
This basic force will cost you $136.75
This army is as easy to paint as Necrons.
Try painting them Chainmail, washing with blue ink, and highlighting with Mithril Silver.
Finish the details and trim with whatever other colors look appropriate. A little Shining Gold and Scab Red should do the trick.
- There are several different HQ options, including Inquisitors and Grey Knight heroes. The Inquisitors have access to their own specialized retinues and equipment. The Grey Knight heroes are close combat monsters
- The grey Knight Marines are a good choice for your troops, but you may also field terminators in this slot for some extra durability.
- The Grey Knights have access to the Storm Raven, a new fast attack option that only a few armies have access to.
- Land Raiders and Dreadnoughts also fit well in this force.
I am told that this can be one of the smallest armies in the game due to the expensive cost of all the troops. They do cost more, but each model comes with improved stats and equipment, making the price worth it. This is supposed to look like a small, elite, hard-hitting task force. Follow the fluff and the army will be successful.