So I saw a few threads in the last few days complaining how the Promethean Knights are tough to kill on Legendary. I was genuinely afraid of how many bullets they took to kill on Heroic. But fortunately, the knights don’t seem to be nearly the bullet sponges they might have been! So I gave a few runs through Spartan Ops and I’ve finished several of the missions on Legendary. And here are the tips I found work consistently for taking out the Promethean Knights.
So here we go!
There are three types: Knights, Battlewagons and Commanders.
The first tip is: (And this is just important for the game as a whole) Kill the Watchers first. Quis custodiet ipsos custodes? Me. I find 'em and I kill 'em. It makes the game easier no matter the difficulty. It doesn’t matter if you’re under fire from a horde of Crawlers or a gaggle of Promethean Knights, if you don’t take out the Watchers, they’ll keep spawning in new enemies and respawning old enemies. You might also want to “thin the herd” around the Knight by taking out the supporting Crawlers. But this is context dependent as sometimes the Crawlers will try to swarm you, and sometimes they hold back to defend a location. Whatever you do though, try to isolate the Knight first.
Next, automatic weapons are your best friends for killing Knights. Precision weapons are only somewhat effective while their shields are up. Coincidentally, the Crawlers that surround most Knights tend to have lots of suppressor ammo to keep you refilled. Once their shields are down you can use a precision weapon if you want. Pulse grenades and plasma grenades are both ridiculously useful against Knights. If you have the Binary Rifle, Beam Rifle, or Incineration Cannon those are the obvious weapons to use. Even on Legendary, the Incineration Cannon is a one hit kill weapon (OHK) on any Knight, even a Promethean Knight Commander, plus they do AoE damage that can trash supporting Crawlers and Watchers.
Lastly, get to mid-distance before taking the Knight on. You want to be close enough that you can hit the Knight with the automatic weapon easily, but far enough away that he won’t transport to you (or behind you) and slice your face off.
My (becoming) standard method is to hit the Knight with the AR or Suppessor until their shields pop. Then chuck a plasma or pulse grenade. If you get the plasma to stick, the Knight is dead. The pulse 'nade will take part of their health. I switch to my precision weapon: DMR, BR or Light Rifle, and aim for the head. I don’t know if the Knights get a “head shot” per se, but they definitely seem to die faster if you shoot their head. If you only have automatic or secondary weapons around, I’d go with two auto weapons while dealing with the Knights. Sure the human pistol can take out Crawlers and you can do that first, but if you can get a Suppessor and AR, the Knight will die far faster than if you try to pistol it to death from what I’ve tried out.
My last piece of advice: Shoot the Knight once while near cover and then watch to see what it fires back at you. Knowing if he has a Suppressor, Scattershot, Light Rifle, Binary Rifle or Incineration Cannon will help you out tremendously. If you see a Halo around the Knights faces, he’s gonna hit you with a Binary rifle shot and you’ll be dead in one hit and get under your cover. If you see four balls of fire, that’s the Incineration Cannon and that’s also a OHK, so make sure you get behind the cover and then back the hell up! (out of the AoE) In that case, you will have to modify your approach on the go. If you can grab your own Binary rifle, you can take those Knights out from extreme long distance and that is definitely my recommended route. Or in the case of any Incineration Cannon-toting Knights, if you get close enough, he won’t fire because he might hit himself. (But that opens you up to getting all sorts of sliced-and-diced, so be warned.) Beam rifles also serves as well and you find quite a few of those throughout the game.
So there you have it. Hope this might help anyone thinking of trying to take on Legendary Promethean Knights.