I pesoanlly think Tearstone of Elune (http://www.wowhead.com/item=137042) is wildly OP with Aman'Thul's Wisdom (http://www.wowhead.com/item=137072), which are the two legiondaries I'm going for. On top of that, add the Artifact trait Dreamwalker (http://www.wowhead.com/spell=189849), and there is some serious AoE potential there I would think.