Steps:

1) Four different champions

2) Each champion wearing two piece sets, repeated three times and each of those sets being 5* or higher while also being level 12 or higher

Yup, still won't complete, and I have spent a ridiculous amount of silver trying to finish

Share a screenshot of something you think meets the criteria and we will correct you.

this, something fixable is going awry

can you please check mines, managed to get two out of 4 but at a loss what two, and what still needs to be changed. You will see they are all different and at level 12

i

@Broker8178 

two notes:

(1) you have a Chestplate at L11 on Thenasil

(2) If the Quest specifically states "Artifact Sets", then using 2 pieces of a 4 piece set may not work. Husk has incomplete sets of both Provoke & Frost. Giscard has an incomplete set of Instinct.

It has been awhile since I saw the quest to make 100% sure. But, yes, all pieces need to be at lv 12. I also think that if you are using the 2 piece sets, you need 3 of those sets on the champion. Where as if you use a 4 piece set, you only need those 4 pieces. Also, if you have it, don't use a set that's 1-9. I think you need all 9 pieces on the champ to complete it which many low and mid level accounts don't have all 9 pieces in a set yet.

If he uses a 4 pc set then won't he need a 2 pc set also on that champ?

a four piece set won't work for this challenge. the only way to complete it is with 3 two piece sets (unless they patched it to accept two pieces from a variable set, but i'm pretty sure they have not).

Variable sets won't work no.  Gotta be 2 piece sets. 

figured as much, but i can't exactly confirm it with my account at this point

Yeah... like I said, it's been ages since I last saw that quest. I couldn't remember if 4 piece sets worked or not. But having 3 sets of 2 piece would be easier in the earlier game to get. You don't even "need" to run a dungeon as you can get them from campaign locations.

Folks, Thanks for your comments. I have 3 sets of 2 on each champion and have upgraded that last piece from 11 to 12, yet it still only shows as 2 completed out of 4 on the challenge screen.

first, go back and double check that you're not still using any gear from 4 piece or variable sets. if you aren't, try removing and reequiping the gear. as i recall, a couple of the challenges had a programming quirk wherein they only counted champions who got equipped after the challenge was unlocked. if that still doesn't work, screenshot your champs again and post them here and hopefully we can figure out what's going wrong.

Bit confused with the 4 piece of variable sets however, managed to identify the 2 champs that were causing an issue by removing a piece of gear and checking the completion drop from 2 to 1. Identifies that Giscard and Husk dropped the completion to 1 so must b3 those two.

i then remoevied all the equipped gear and put 3x2 on each of th3m and upgraded to lvl 12, no change......!

I will post a pic of each below.

gear sets in this game come in three different types. two piece sets, which provide an additional bonus when you have two pieces equipped to a champion (which can be stacked, so having 6 pieces from one of those sets would provide the bonus 3 times), four piece sets, which require four matching pieces to provide a bonus, and variable sets, which will provide a bonus regardless of how many pieces you have, but the more pieces, the better the bonus. each gear set will show you what type it is next to its name in your artifact storage, as shown below (two piece set marked in pink, four piece blue, variable green):

i

right now all the artifacts on your champions comes from four piece sets (other than husk's chestplate and boots) which doesn't count for this challenge or provide any special bonus to your champions in general.