I checked the artist's page on the source link, but I'm under the impression he is simply that creative at LEGO, not that those are special kits...
I mean, some custom LEGO model builders create and share instruction booklets so you can make their work at home, but I imagine this wasn't the case here
God, looking at all of the stuff about cool custom characters makes me want to flush out my own Craftworld a bit, Hara-Sion shall take the fight to the corrupted kin and all else who stand in our way!