On Lucian youmuus? or essence reaver? First

Well those were...words.

Anyway I think Youmuu's is still the go-to if you need early game power/are already snowballing by your first back, but ER is a better mid-late game choice because HOLY SHIT 30% CDR AND ALL THE MANA YOU NEED. All in all I PREFER crit Lucian but standard "Imma just kick your ass" Lucian has his place too.

Youm, hard to lose early-mid with youm, you can be behind in lane and come back with youm. The components to youms are easier to buy too and has great passive to boot. ER doesnt help you much in lane except for mana and the occasional crit. Youm gives you armor pen, ms, attack speed, and alot of AD which are amazing to have early-mid game for ONLY FOR ONE ITEM. Its a great ADC item, I've been preaching it for years but no one believe, youm adcs are really good, better than crit because its consistence damage over relying on crit.