I did find it with Better Wardrobe, although I didn’t know you could actually buy it from vendor. It’s sold from the normal raid vendor for the usual 5000 bronze.
Here’s a simple mog that uses the whole set, plus some extra like cloak and the two swords: https://www.wowhead.com/outfit=533371/timerunner-king
The thing is, it’s the only case where there’s an exclusive recolor of a tier set, it’s even categorized seperately as “Timerunning”, like the Timewarped ones we get from Mage Tower.
I hope it can be useful <3