User blog comment:Care Level/Dunk Marathon Darius: The Toplane Experience/@comment-6061249-20140603170147/@comment-9593635-20140603221128

At lvl 18 with 21/9/0 and LW, you have 55% armor pen and 20 flat pen. That means that a target with 100 armor ends up with 25, and a target witth 200 ends up with 70. Without LW, you'd be looking at 30% total pen, so your 100-armor target ends up with 50 (25 armor more, which is literally twice as much) and your 200-armor target ends up with 120 (50 armor more).

Let's say your 100-armor target has 1.5k health (they're a squishy); that 25 armor is 400-ish effective health versus your non-ult, non-bleed damage. Against something with 200 armor, let's assume 3k health (which is on the low end); that 50 extra armor is 1.5k effective health versus your non-ult, non-bleed damage.

Nothing you can buy for 2300g is going to give you the same amount of disgusting damage as LW past midgame. The closest you could get is, like, a BF sword and a pickaxe (70 AD), which would give you around 650 raw damage... which is then reduced to about 400 on a 60-armor target. LW gives you 40 AD (around 350 raw damage) and increases the damage from all the rest of your items, so it's hands-down the best item against anything with more-than-paper armor.

Also, you don't max your E until last, so LW gives you a huge chunk of % pen in the midgame, where normally you wouldn't have it, so you don't get huge % pen amounts until enemies start really building armor.

At least give LW a shot; experience the chunkening.