User blog comment:Deshiba/Circumventing armor for marksmen/@comment-24420226-20150520230856

I would direct Marksman interested in additional Armor Penetration options other than LW towards Youmu's. It has a lot of the additional benefits of Cleaver (CDR, AD, Penetration) while also providing a nice care package of stats that ADCs are already interested (critical chance, and a move/attack speed steriod for kiting). It does fall of later in the game as Flat penetration starts to matter less, especially in full AD comps, but it is a fast pick up for mid-game power spikes. Generally, Youmu's works better than say statik or PD as a second or first buy if your strategy or comp revolves around picking fights that won't last much longer than Ghostblade's active. I'm not sure if new Ashe fits into this category, as she ideally needs a few seconds to ramp up stacks on her Q before bringing her full damage+slow potential, but the movespeed and attack speed steriod could work really well on her.

As for TBC, you only really get it on champions that can reliably stack it across multiple targets very quickly. Wukong is probably the best example - his ult alone can get 4 or five stacks on almost the whole team if they are grouped tightly enough. For Marksman, Sivir is probably the best to do so with widespread AoE damage from her Q and W. The potential benefit of being able to stack Cleave with just one auto attack with Ashe's newi Q s moot since, as as stated before, she needs to get a few shots off before fully stacking Ranger's Focus.