I tried out some new units from Grey Knights including the Brotherhood Ancient with the Relic Banner, the Chaplain, and a Psycannon Purgation squad. The D6 wound smite is really powerful, along with the normal Banner buff. The Chaplain did help land some hits, and the Psycannon purgation was ok, but really only shined with the strategem and the Grand Master buff.
We did the standard Maelstrom of War mission. I won 15 to 7 with literally 4 models on the table and a total of 7 wounds. It was a crazy close game.
Of course, here are some pictures!