I like to share an observation. I don't know if this is something new or not, but I was seeking the The Fabled Crypt Wurm and it just wasn't spawning. I found other named like The Fabled Crypt Devourer and the like and it seems like the fabled loot drops are random because I looted the Fabled Obtenebrate Short Sword off the The Fabled Crypt Devourer. So just chase down any fabled in the zone, It may have the sword or drop you want.
60 paladin 184 AAs with 62 ranger, 62 cleric and 65 cleric took this down in about 3 or 4 minutes. Slow was key. It kept trying to proc Dooming Darkness on me. 838 was top hit. Most hits were around 200 - 400. Enrages around 10%.