There is no doubt that Knights are powerful units and bring the sting. However, as strong as they are, they need support to keep them operational and on the board. So I have three Knights and I want to fill out a 2000 pt list. What do I bring to the dance?
Note: I am thinking Unbound List with my unit choices here. I know you end up giving up stuff; just looking to put together a fry up of leftovers sitting around in the proverbial kitchen. Also, there is always a need for Objective Secured units to hold onto those VPs. This commentary will focus on units to provide support to the Knights. Finally, talking a friendly game here, not competitive, and certainly the potential for much cheesy goodness.
Onager Dunewalkers: If I'm concerned with my opponent bringing Flyer spam, these guys are just the ticket. Put an Icarus Array on each one, and those Flyrants aren't so scary anymore. Not only does Icarus have Skyfire and Interceptor, but a solid number of shots as well. If a Marine player decides to try a Drop Pod assault, that Interceptor could cost my opponent a few points and short circuit that tactic. I know you can drop a Twin Icarus Autocannon on a Knight, but we are only talking two shots each. The Autocannon also takes up a slot that could be used for things like a Stormspear.
Wyverns: A squadron of these "barrage factories" would be great for handling horde armies that will try to tarpit those Knights. Not having a Guard dex, I am thinking we are talking four templates each that ignore cover. That could take a tidy chunk out of some mobs or broods.
Dominus: These Cult Mechanicus HQs have the ability to patch up stuff on a 2+ in addition to other benefits. So why not put one of them next to each Knight and patch up those scatches? If you take the Exalted Court formation for the Knights, you could give each a Mark of the Omnissiah and add It Will Not Die. The Dominus combined with the IWND could make it very tough to kill a Knight model. I would of course need to put some bodies around the Dominus to keep alive, but I would consider that a carrying charge.
Librarius Conclave: (Disclaimer: I am relying on podcast discussions of the Conclave as I do not have a Marines codex in hand for details of the formation rules). I am really excited about this new formation, and it has the potential to really cheese out a formation of Knights. Not only does each Librarian in the Conclave get essentially almost any power they want because of power sharing, they also can get manifest on a 2+ (rerolls for Tigerius). Why would you not cast Invisibility on those Knights? How many other powers could you use to buff these Knights in addition to the buffs given by Knight formations? With a bit of consideration, the Librarians have incredible potential to truly make these Knights insanely good. Just to rub salt into the wound, I might also bring a few squads of Paladins to put the Librarians into for ablative wounds, getting 3 more Psychic dice in the process. Even with just 3 Librarians (and the Paladins) in the Conclave, we could be talking about 10 Warp Charges before a die roll.
Kataphron Destroyers: Can you say 36 (are they Relentless? If not, that would be 24 shots with a 4/6 Salvo profile) x 36" range (counting their 6" move) Grav shots? I sure can if I take two units of three of these little fellas on tracks. They may only be BS3, but with buffs from other Mechanicus units, that could easily go to BS4. Lots of Grav goodness to discourage Melta toting models from getting too close. These guys are also T5 with W2, so they can certainly take a pounding.
I think there are lots of options to provide my Knights with the support they need, especially with all of the units available from the Mechanicus and the new Marine codex.
What would you take to give these Knights the backup they need and fill out that 2000 pt list?