Manamune or Essence Reaver?

Because essence reaver is useless and prohibitively expensive.

I think Urgot and Sivir can both make use of essence reaver. That's about it, though.

Essence reaver seems like a decent late game item on Ashe as an alternative to Bloodthirster. It gives her a viable late game item to turn her Vamp scepter into, as she benifts from the CDR, high AD, and the mana steal mechanic allows her to just turn her Q on and forget it regardless of how high her AS speed gets. Otherwise you end up having to micro manage it or risk going oom.

It feels better than muramana on her which has nothing useful she can build early. Yes she can stack tear quickly with Q, but she doesn't really benift from the mana pool boost until the item is completed. A Vamp Scepter is almost always a cheap and useful item on her, and if she still has it late with a lot of gold there are not many better options she can upgrade into.

muramana + iceborn + bork + last whisper = chunk half a tank's health.

Because people hate ER with a passion. It's not terrible, it's just something most ADCs don't need.

I've been trying to learn Blue Ezreal, but I usually try and get both. Manamune is the one to get first since it's stack reliant, then I keep my mana and damage up with the Essence Reaver.

How does Ashe not make use of those stats? Critical reliant ADC benift tremendously from AD. While she only has 2 major spells she casts, CDR on both of them increase their utility greatly and many guides advocate for similar items late like Zypre on her for similar reasons (AD + CDR = good). As a champion who needs Lifesteal and something useful to build Vamp scepter into...she benifts from that too.

The mana on hit makes her Q last forever...FOREVER!

No one is saying it's core on her or even a great pick every game, but late game as a 5th or 6th item you upgrade your Vamp scepter into...you basicly have BotRK, BT, or ER. I personally think it provides the best balance of what I need at that stage as I get AS from other items, and I find the stat better suited for a utility minded ADC that Ashe is in the late game.

Just try it sometime. You may be suprised how good it feels.

Manamune hurts more for Ezreal and gives spammability earlier. Simple as that really. ER can work, but muramana really gives a lot to on-hit type champions.

To put the question back on you: why would ER be picked more than muramana?

I can see your point and I will leave this conversation with a few final thoughts before it turns toxic.

1. The extra 10% lifesteal on BT is absolutely a good stat late game, but it costs 300 gold more. That's a fair cost, but you still have to farm that gold, delaying the item.

2. The mana regen is not worthless, though I'll admit situationally useful. It's more powerful when your team Is ahead seiging towers as the CDR and nearly infinite mana allow you to spam your frost shot as safe AoE poke much better than if you didn't have those effects, and still have mana for your ultimate and Q when you need it once a fight goes down.

3. The shield while obviously nice, is also only situationally effective and is best used as a defensive tool to counter seiging as it allows you to absorb poke while clearing minions safely under a tower. It's harder to keep it fully charged in offensive pushes for very long and without any resistances in ate to her kit, it barely provides any real defense against burst damage assassins or mages. Still, it's got its uses for sure.

4. The discussion of ER vs BT on Ashe late game is rather moot, as both items would be purchased after IE, SS/PD, LW, Boots2, VS + BFS. If I back and am 299 gold short of BT I'm buying ER, and if I'm 19 short I'm probably waiting for BT, especially if we are defending.

Good discussion though. I appreciate your points. Good luck on the fields.