Recently we beat Dynanis Buburimu. We learned that after killing the Mega Boss the Nightmare mobs pop in the area. (In Qufim they're up before you kill the Mega Boss).
We killed necessary dragons/NM's to negate the MB's 2 hour avaiabilities (he has them all and will use them more than once), and then started farming Nightmare mobs.
Nightmare mobs drops AF2 accessory items, (i.e Belt, Cape, etc.) This is what I was after: