After landing 3 basic attacks, Master Yi's next one within 4 seconds strikes twice, dealing 50% ADbonusphysical damage which applies on-hit effects and can critically strike. If Master Yi's primary target is killed before the second hit can go off, he automatically attacks another enemy within 300 range.
Double Strike's first one both triggers it as well as resets the counter (even if it kills Master Yi's target) while the second one acts as the first stack for the next Double Strike activation (continuous attacking will cause it to occur every 3 basic attacks, or 2 if Guinsoo's Rageblade is purchased)
Alpha Strike's damage is calculated individually on each bounce. It is possible to inflict differing amounts of damage during an Alpha Strike chain if Yi loses Wuju Style's passive AD bonus in the middle of Alpha Strike.
Alpha Strike applies damage after Master Yi leaves untargetability and thus can attract turret aggro.
Passive: Champion takedowns reduce the current cooldown of Master Yi's basic abilities by 70%.
Active: For 7 seconds, Master Yi gains bonus attack speed, multiplies his total movement speed and becomes immune to all slows and cripples. While active, champion takedowns extend the duration of Highlander by 7 seconds.