Essence Flask (A new component for Essence Reaver)

NEW BUILD PATH Pickaxe(875) + Long Sword(360) + Essence Flask(1760) = Essence Reaver(3500/505).

ESSENCE FLASK Build Path: Forbidden Idol(700) + Vampiric Scepter(800) = Essence Flask(1760/260) [Stats] +25 AD +10% CDR +10% LS Passive (Unchanged/Slightly nerfed): Your basic attacks restore mana equal to between 1% and 4% of the physical damage dealt, based on your missing mana.

ESSENCE REAVER [Stats] +80 AD +10% CDR +10% LS Passive (NEW): Your basic attacks and abilities that deal physical damage restore mana equal to between 2% and 8% of the physical damage dealt, based on your missing mana. The mana restored from the abilities can only proc once (for example if Jayce hits multiple minions with his Q, only one will return mana to him).

PROS -Nice build path (components are cheap and easy to get; no B.F. sword); -Essence Flask is useful in lane and can be upgraded later on (like Cutlass); -Essence Flask gives everything that Essence Reaver gives very early in the game; -Champions who are good with Essence Reaver will have more incentive to buy it; -Nothing is buffed except the passive with added abilities using the proc of essence reaver (damage and CDR is still the same);

CONS ...?

Thoughts?