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)
Master Yi becomes untargetable over Alpha Strike's duration, and can critically strike, dealing 60% AD × (1 + bonus critical strike damage) increased damage to all enemies. Basic attacks reduce Alpha Strike's cooldown by 1 second.
Alpha Strike's damage is calculated after Master Yi exits untargetability (Bonus AD from auras will be factored while the tooltip displays the total bonus damage from a critical strike)
Master Yi will be focused by turrets once he exits untargetability (if he is the only one in range of if he hits an enemy champion) while neutral monsters will stop doing so during it (they do not reset their health)
Alpha Strike can be used to dodge and avoid damage from enemy skillshots, enemy area of effect abilities (Time Bomb, Absolute Zero, Requiem) as well as enemy single-targeted ones (except Urchin Strike) but will also dodge allied abilities (except Wish)
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 movement speed and becomes immune to all slows. While active, champion takedowns extend the duration of Highlander by 7 seconds.