Comments posted to our Dark Souls 3 Wiki
Run to the LEFT as soon as you reach the top of the staircase, hug the circular wall until you find an arch leading to a rectangular section of roof. This section of roof is safe, you can easily kite the twin-axe knight onto it. If you aggro the first halberd knight on your way to the roof, you can pull him onto the roof and kill him, the twin-axe knight will not aggro to you if you are on the rectangular roof.
Once you deal with the twin-axe knight, the other two can be fought one-on-one where they are.
This method does not require any special rings or spells, leaving room for the Gold/Silver Serpent rings. Hornet ring is also useful for faster kills.
I've been using this method as a melee only character, it's very safe as long as you can reliably kill the knights one-on-one.
As stated above, keep circling and fish for backstabs. Backpedal as soon as you see windup for either the spin attack or Pillars of Light.
Artificial difficulty with wings.
Artificial difficulty.

Thank god I found this page, I've been killing them myself and it takes too ***** long. This is so much nicer
Never tried to edit an article before so not sure if we even can. Anyway, Soul yield with conventus ring (regular), shield of want, simbol of avarice: +- 25k on NG
You can get your total to 30K if you use the Mendicant Staff in your right hand and Shield of Want in your left. You don't have to use sorcery, either, just switch to the staff right after you kill them and right before the souls are rewarded.
In NG+2 you can equip 2 shield of want in both hands along with the covetous ring and single of avarice and kill them. As soon as one of them dies equip both the shield of want for more souls
Do other soul farming items stack? CSSR and CSSR+1, Mendicant Staff in each hand? Just starting NG+ and I wasn't going to bother picking them up.
Yes, all the items that increase the amount of souls you get stack with each other, but you cannot have more than one silver serpent ring equipped, so you're best off using the best one you've got.
I believe the Mendicants staff will net you more souls than the shield, but I may be wrong
anybody elss have the glitch where the silent ring and spook doesnt work on them. 2 out of my 4 saves have this glitch, the hear me no matter what. Very frustrating
just use rapport
I can't be the only one who wants their armor/weapons in gold, right? In dark souls 2 they did a thing were they gave stuff to players before their release of a dlc, and the last thing they gave was a weapon already in the game, but blue. Why not do the same with the golden weapons of the winged knights.

If you're willing to put in the points, smoughs armor is both.
^But Smough's armour is hideous. We need Holy Emperor Angel Armour complete with wings.
Smough's is bronze, not gold. That and though Smough is a beautiful angel with moobs, he doesn't have angel wings.
Direct reference from berserk. Winged knight ascended.
you can permanently stun lock them with sacred flame just wait for them to finish their combo and use it then recast it as they are getting back up for a very easy fight, im in NG+ and with 29 faith and 30 int i deal around 780 dmg with the witch ring and the great swamp ring i hit them 3 times and they survive with very little hp which then i just hit them with a weapon and they die.
The following takes a while, and I'm not proud to admit I did this, but it's pretty safe and just thought I would add it case someone else was having a hard time beating three of them in a row.

On the roof where you lure them too, there is an opening in the back right corner that leads to a platform, from that platform you can drop to where you fought the three NPC's. Lure the winged knights one at a time, down to the opening and jump to the first platform. Usually, they will jump all the way down.

From here there are a couple of options, you can either start using projectiles until you kill them. Or, you can wait till they are under you so you can get a high damage plunging attack. Then run away as fast you can back up to this spot (they will stay below) and do it again. Sometimes, they will walk into the building all the way to where the two handed lothric knight is standing. If this happens, it is possible to slowly walk up to them until you're behind for a critical. Run back outside the building (as this will aggro the lothric night as well), wait for them to reset and do it over again. If they reset in a manner that faces you, throw a projectile, run away and wait for them to reset again. They usually reset in a manner that will let you critical attack them without fear of aggro.

Again, not proud I had to do this, but it was easy and safe and didn't require any estus.
NOTE, forgot to mention that sometimes they don't jump all the way down and get stuck on the first platform. If this happens, jump all the way down and run as fast as you can back up to the roof. You can get a plunging attack on them dropping down to the first platform. Rinse and repeat. If they drop all the way down with you, follow above.