Lets talk about LC...

my usual build is

boots>basi>blink>blademail>bkb>A/C>skadi>BoT's then into a luxury item.

hmmmm good points lads :)

Why not, Boots, Blink, BM, BKB or Sphere depending against the enemy pick, and then luxury items?

agreed my core items are BM BKB Blink.

i sometimes swap A/C for Mjollir and skadi for satanic.

you can go quite variable in ur builds but depends on the enemy

Dont forget that snipers Headshot slow is nothing to joke about either. I think the cooldown on duel is too high for her to be usefull because when duel is off cooldown she is more or less a big creep.
She would need a slow to help supports catch up and do something. Once 5maning starts you cant even duel a support without dying after. I like her but imo she is very weak compared to current meta carrys