Imperial Knight Allies: Grey Knights, Inquisition, and Assassins
Continuing in my theme of Imperial faction allies for Imperial Knights, we've got the more sinister branches to consider. The Grey Knights, Inquisition, and Assassins all bring some interesting, yet expensive toys to the mix, so lets talk about how we can use them.
The Grey Knights were once the most elite army in the game, now they're the second most elite, Imperial Knights obviously now being the most elite (in terms of expensive units in the army). When you combine the two armies, you're obviously going to have an incredibly small army. The Grey Knights themselves do not have any fast, cheap troops, so immediately, you shouldn't even consider an Allied or Combined Arms Detachment and go straight for the Nemesis Strike Force (NSF from here on). When you take the NSF, you're basically taking an Allied Detachment, but with double the allowances (and actually up to 4 elites). So the question, what do Grey Knights bring that can help Knights?
Anti-transport. My favorite unit in the Grey Knight army simply has to be the Nemesis Dreadknight with Heavy Psycannon. Currently, the biggest bane to Imperial Knights is cracking Rhinos and their ilk efficiently. Firing a rapid fire battle cannon at a rhino to only do 2 HP is a horribly inefficient way to get to the gooey bits inside, but 6 S7 rending shots from a Nemesis Dreadknight can get into one much more reliably. Once you've blasted open the vehicle, the guys getting out are then going to have to deal with taking a couple rapid fire battle cannon shots to the face.
Aside from Nemesis Dreadknights popping rhinos, the Grey Knights do bring a few other interesting units to the game. Through the use of the Nemesis Strike Force, you are able to get very resilient and/or hard hitting units, anywhere you want on the board. Interceptors (and NDKs with Personal Teleporters) are great for getting up close and personal with the enemy quickly, and if you need to grab a Maelstrom point in a pinch, you can make your 30" shunt to grab it.
The obvious downside to running Grey Knights as allies though is that you'll have an incredibly small army, no matter what you take. Because of this, you'll have to play very carefully and probably sit back with the Imperial Knights whenever possible to hold onto back/midfield objectives. Also, outside of taking the Storm Raven, you really do not have any anti-air, and unfortunately taking the Storm Raven will quickly eat into the points in your army. Typically when running GK as allies, I just ignore the air and hope for the best.
My 1850 Imperial Knights + Grey Knights list:
Knight Errant: 370 Knight Paladin: 375 Cerastus Knight Castigator: 380
Grey Knight Librarian: 110 5 Grey Knight Terminators: 2 Daemon Hammers, 2 Nemesis Falchions, 1 Halberd, 1 Incinerator: 205 Nemesis Dreadknight: Nemesis greatsword, heavy psycannon, personal teleporter: 205 Nemesis Dreadknight: Nemesis greatsword, heavy psycannon, personal teleporter: 205
Occasionally I run a second Paladin instead of the Castigator to run the Adamantine Lance, but I'm still really enjoying the versatility of the Castigator. The whole army has 11 models, so you can imagine how careful I have to be to avoid unnecessary waste, there simply isn't room. Even though this detachment of Grey Knights is very small, it awards me 5 Warp Charges, and brings the army up to 20 S7 shots for blasting open transports.
While being an incredibly small subset of allies, the Inquisition brings some very unusual options to the table. Generally, I don't particularly care for Inquisition with my Imperial Knights because they lack versatility as an army, but they really shouldn't be totally ignored.
The first thing that you should consider with Inquisition is obviously an HQ, as it's the only required unit in the detachment! The named characters are pretty fun, I really do love Karamazov and his oversized rascal scooter, but unfortunately, he doesn't' do a lot for the army and can't be transported. Coteaz is always a popular choice, especially since being alpha-striked by drop pods is the bane of the Imperial Knights. By taking him, you can park him behind your Adamantine Lance Formation, basically denying the opponent the ability to safely com in to the rear of your formation. The other HQ option I like is simply an Inquisitor loaded up with Servo Skulls, which are great at stopping any pre-game advances made by the enemy, and simultaneously making your rapid fire battle cannons more accurate.
Inquisitorial Henchmen Warbands will obviously make up the bulk of the detachment, and when we go back to thinking about filling the gaps in the Imperial Knight army, it doesn't look good. Imperial Knights need scoring bodies and anti-transport first and foremost, which means any Henchmen Warband that you take should absolutely be mounted in a Chimera, Razorback, or Land Raider. The firepower that they bring should focus on killing enemy transports, so the Chimera should go double heavy bolters with psybolt ammo, the Razorback should have psybolt ammo, and you could even consider the standard Land Raider. It's important to note that the chimera still has 5 firing points for Inquisition, so it's really a solid bunker for meltaguns. When it comes to the guys inside you should consider Ministorum Priests with plasma guns, Acolytes with melta/plasma guns, Jokaero Weaponsmiths, and Servitors, possibly with a couple crusaders to take punches.
Like Grey Knights, the Inquisition doesn't really offer much for anti-air, only bringing the Valkyrie, which is miserable in this role.
Sample 1850 Imperial Knights + Inquisition List
Knight Paladin: 375 Knight Paladin: 375 Cerastus Knight Castigator: 380
Ordo Malleus Inquisitor: Psyker Level 1, 3 Servo Skulls, Terminator Armour, Daemon Hammer, Psycannon: 119 10 Henchmen: 6 Acolytes (3 meltaguns), 2 Crusader, 1 Jokaero Weaponsmith, 1 Psyker; in Chimera with 2 heavy bolters and psybolt ammunition: 189 12 Henchmen: 9 Acolytes (3 meltaguns), 2 Jokaero Weaponsmith, 1 Psyker; in Chimera with 2 heavy bolters and psybolt ammunition: 206 12 Henchmen: 9 Acolytes (3 meltaguns), 2 Jokaero Weaponsmith, 1 Psyker; in Chimera with 2 heavy bolters and psybolt ammunition: 206
Ultimately lacking in anti-air, you end up with a fair amount of melta, quite a bit of Divination (as well as +4 Warp Charge), 18 S6 shots at range to help kill transports, and some servo skulls to keep the enemy back. While nothing is Objective Secured, you still have a good amount of scoring from those large henchmen squads in chimeras.
Finally to tie up this article, we're on to the Officio Assassinorum, which was once part of the Grey Knights, but now a stand alone force. Right away, if your local meta only allows 2 detachments, the Officio Assassinorum is going to be a bad choice, unless you're playing some very oddly specific point values. Since there are only 4 options here, we may as well go over them all.
The Vindicare Assassin brings a pretty nasty gun that can get lucky and pop transports from a very long range, but is usually only going to be responsible for 1 HP of damage per turn. As a scoring unit, he's not bad though for sitting on backfield objectives.
The Callidus Assassin wont be wrecking any transports for you, and generally wont be that hot for sitting on an objective, but she can hurt dug in infantry squads quite well. Unfortunately, in the end, she's not really bringing a lot that Imperial Knights need.
The Eversor Assassin is my favorite assassin, but even less useful to Imperial Knights than the Callidus! He's fine at beating up hordes of useless infantry, but so is a rapid fire battle cannon or acheron flame cannon.
The Culexis is the only one other than the Vindicare that might actually be helpful to knights. He's hard to hit and easy to hide, making him the perfect model for camping an objective and not giving it up. His gun can be fed all the warp charge you generate to try and blast open transports before he mulches the guys inside.
Overall, as much as I love the assassins, they really don't bring a lot to Imperial Knights.