so eclipse gives you 4% armor pen and 5ms on legendry items and ldr gives you 30%
so 34% on second item
third item i go black cleaver because there is a "feature" that makes eclipse proc with one auto or just q which is good in the mid game
plus it gives you more hp and cleave passive is really good at six stacks it gives 30% armor reduction and 18 ms
you can go IE third then black cleaver if you want more damage and they have no armor
bloodthirster is a really good item with a very high ad and the highest lifesteal ration
senna does bonus damage that has 100% lifesteals effictiveness
at three to 4 items you melt tanks oneshot squishes and very hard to kill
the bonus ms you get will help you postion better and kite really well

you can buy boots whenever