Given how this was the most extensive of the Empire photosets, it does appear that the Mercenary has developed an accidental specialization in Urizen costumes. We do seem to tinker and there have been many, many variants on "elven" robes in slightly different shades, cuts and weights of fabric. I do think we've come a long way from the first generation of elven robes.
The Slander Rat is in the cream renaissance gown that appeared in the League photos. The extensive train has been pinned up in these shots and form more draping folds from her waist (though it is mostly hidden by the pooling velvet robe). She also wearing the Egyptian cultural armour she and the Ginger Ninja made for Odyssey (though I believe that set is actually made for the Ninja). She is holding a Lorien Shield and a fey sword, both from Character Kit.
Thus were born many jokes of how flirting between Urizen couples need happen via the medium of semaphore (the Proprietor and the Slander Rat star as a pair of star crossed lovers on the opposite sides of a flying buttress who cannot bear to approach each other any further) and the inconveniences of secret wizardly cabal meetings (thus being unable to whisper properly at each other). The Proprietor also quipped that all Urizen, no matter their actual skillset, look like wizards.
These photos were around the back of St Giles Church, where once two prince bishops (one true, one false) fought for the control of County Durham. Or so I'm told. There are a lot of long, low shots with the walls and church windows, hopefully with the careful cropping give a vague sense of the spires and towers of Urizen.
The long sleeveless robes that are being worn as the outermost layer in most of these outfits do not appear to be particularly compatible with larp fields, though they are quite that long in part so that they still look good (by having sufficient drape) when you pull the train over your arm to carry it when walking. It can, of course, be commissioned shorter.
We did run out of pale under robes and the Battle Librarian is wearing a pale blue peplos under the various blue robes he has on. The Proprietor is wearing as his base layer a cream robe that could legendarily fit three people (it was once a bedsheet).
Of the props, the naginata is from Eldritch. The black leather crown is from Nordavolk. The necklace worn by the Pillywiggen, I believe, was made by Sara Emmims.
The white and gold shield (also having appeared in the Highguard shots), the pike and the fey swords can be purchased at Character Kit. The velvet robes (midnight purple, grey and beige brown), the cloak with a hidden pocket and the various sets of faux silk elven robes (greens and blues) are also on the website. The Proprietor is in a gold elven coat, which is also available in green. The various robes can be commissioned from the Mercenary in different combinations and fabrics.
More photos of the Dreaming Spires of Urizen under the cut.