Watcher's eye what build can use this?

Which builds can this be used with?

Its all irrelevant except for the 1.22% general leech which is very impressive, you'd have to run vitality which is a mild potato aura obviously but for a caster its difficult to get 1.2 spell leech outside of warlords, warlords takes up a curse slot and is diminished on bosses.

So basically your looking for any caster looking for a leech source.

That's pretty much ideal for anybody wanting to run a self-cast Incinerate due to leech + reduced mana cost of skills both being very good for such a build, and very good for any caster that desires life leech.

(Yes, I know, not many self-cast Incinerate builds around these days for good and obvious reasons, but that jewel would help a lot alleviating Incinerate's mana issues.)

The vitality doesn't need to belong to you. Seems like it would be good for partying. For solo, you could even pop it on a totem when you need the leech.

As for clarity, blade flurry benefits a lot from -8 mana cost, and lvl 1 clarity is quite a cheap way to get this. Use an elreon ring too and pay no mana.

Yeah the reduced mana costs can be cool, too, since you can use a level 1 clarity to get it, reserving almost nothing of your mana.

I'd echo the 'Spell Leech' recommendation. Vitality may be a less-than-awesome aura, but you're getting the leech as well as regen, and as stated the mana cost reduction can be obtained for nearly free. Blade Flurry, Blade Vortex, Incinerate, anything else that requires rapid-fire casting could benefit from this one. I could see using this with BlasWarlord on a Blortex build to get 3.2% total leech, as well as increase effective leech on bosses. Alternately, some of those crazy hipster Incinerate CWC builds could have a lot of fun with this.

Alright ty, that does sound promising. Though I am not sure wheter it's going to be viable still once the update comes through.