The Pheonix Clan has constructed special Wraith-Constructs designed to fight the Daemons of Chaos, using skilled Spirit Seers to bind the souls of dead Warlocks to these new WraithGuard Knights. I will be using the rules for Grey Knight Terminators.
In addition to converting WYSIWYG weapons (with Eldar aesthetic, of course), I painted all of the heads silver and mostly red bodies so that they stand out from the rest of my "true" Eldar. This way it will be simple for my opponent to see the difference: Silver heads w/ blue CC weapons= Grey Knights.
I used axe handles with wraith swords to represent Halberds, Necron staff + bits as Hammers. I magnetized the arms of the 'Justicar' and 'Librarian'. Using the Nemesis Strike Force detachment, I can simulate these models coming out of a Webway Portal (turn 1 deep strike) with a 1-turn "Battle Focus" (Rites of Teleportation)
Wraith Dread Knights:
These were previously made to be jetbike riding WraithLords that I could use as WraithKnights, but the change from Monstrous Creature to Gargantuan has made them look too small. However, they are perfectly sized as "count-as" Dread Knights with personal teleporter (i.e. the jetbike). The rules even simulate a 1-turn "turbo-boost" in the form of the Shunt move. I even magnetized the under-gun to with the barrel of a Psilencer, which I think looks more like what a Psycannon should look like.
Another 'fluff' point to address is the fact that Grey Knights are only Allies of Convenience, not Battle Brothers. Since I am using the fluff that they are actually Eldar, I explain this as being the "new/unknown" nature of the Wraith units. Outside of the Forge World WraithSeer, no other Wraith construct has Psychic powers. Combined with the Eldar apprehension of using "Necromancy" in the first place, this makes the living Eldar a bit wary of direct contact with these constructs. They will fight along side them, but not directly interact with them. Hence they act more like Allies of Convenience, then Battle Brothers.
The Owls have a psychic link to the 'Inquisitor'. They count as Servo-Skulls