Takedowns on enemies grant permanent Attack Speed.
Offense
+9% Attack Speed
Flex
+5 AD or 9 AP
Defense
+6 Armor or 8 MR (match-up)
WhyPhase Rush
Phase Rush on Quinn allows you to stick to your target for repeated follow-up damage and kill secure.
WhyManaflow Band
Manaflow Band is huge for Quinn, empowering your ability to poke and keep sustained harass damage up.
WhyCelerity
Celerity massively empowers Quinn's strongest attribute; Her ability to traverse the maps for roam kills.
WhyGathering Storm
Gathering Storm allows you to scale into the late game where you might otherwise be quite weak.
WhyTriumph
Quinn is naturally a squishy top lane that relies on her ability to burst down a target. The big heal from Triumph after kill an enemy can be the difference between a 1 for 1 trade and getting out with the kill alive.
WhyLegend: Alacrity
The bonus Attack Sped from Alacrity is huge for allows you to deal consistant damage in teamfights where you have a front-line or need to shred down a tanky target.