Essence Reaver needs a touch-up.
I have a few thoughts on this item. Because of the meta, the item has been really weak. Personally I would like to see this item used more in competitive play and games in general.
The Problems: -The item is very champion specific, mostly for AD champions that have expensive abilities or use them very often. -Has been touched by Riot since 4.15 -IE is the most used ADC item and is essentially stronger. -Outscaled by most ADC items
Lets compare this item to Blood Thirster-
BT gives
80 AD 20% Lifesteal A shield with 50-350 depending of the level
Essence Reaver gives
80 AD 10% Lifesteal 10% CDR A mana regen on autos
And is 300 gold cheaper
The problem is that it gets outclassed by the Bloodthirster at the moment. Why? Because the Bloodthirster scales better (higher lifesteal that scales with the multiplication-marksman-build + shield)
Personally i think that the Essence Reaver, considering it's passive should be an earlygame/midgame-item when manaissues really matter. So i dont see a reason why it should compete for the 80AD-BF-Sword-Slot. Like many others before mentioned, the manaregen comes too late to be useful enough to warrant it's weakness against the Bloodthirster.
Through the nature of its passive, Essence Reaver should be an inexpensive item. Well, here we are. Maybe rework it into a new item for mana heavy ADCs like jinx, ezreal, and maybe graves or lucian.
TLDR: Essence Reaver needs a buff or rework for mana heaving champions as other items outscale it.