Rhaast is better all-around, but that is simply because SA cannot function when behind. If you are fed (4+ kills with only 1-2 deaths) SA can do as well as Rhaast if not better. Dark Harvest works well on Kayn in general, with its rework it also works for Kayn top. The Runes in this build are semi-outdated, with celerity being reworked to not give AD anymore, and DH being reworked to outclass any other rune for Kayn.

thanks

i am pretty sure it does. lethality is the name of a stat which the item grants not an item effect like spellblade. the unique passive part only triggers when you buy two of the same item. buying two duskblades only gives you 21 lethality but buying a duskblade and a Edge of Night would give you 39 lethality. so buying an Edge of Night and a Youmuu's Ghostblade would give you 36 lethality. so in fact this does give you the full amount of lethality. the actives also lend themselves well to the playstyle of shadow assassin kayn. in fact, with all three Serrated Dirk items ( Duskblade of Draktharr, Youmuu's Ghostblade, Edge of Night) and triggering Sudden Impact, you will have the second highest lethality in the game at 64. the only way to get more than this is to buy another [serrated dirk]] on top of this giving you 74. BTW this is the first comment that someone has posted on one of my guides so thanks! if there is anything i can do to improve please tell me!