Xayah, a high skill and fun to play ADC that deals great damage and feels damn satisfying to play properly. Here's a guide I threw together to summarize the basics of the champion and get you ready to play/play against this edgy avian.

-Passive-
Everytime Xayah casts a spell, she gains 3 feathers that shoot out in a line whenever you auto attack, leaving a feather in the ground for 6 seconds. Xayah stores up to 5 feathers that goes away after 8 seconds of not attacking. Xayah can also recall with rakan

-Q-
Xayah shoots out 2 feathers in a line, dealing reduced damage after the first target hit.

-W-
Xayah gains a buff that increases her attack speed and her autoattacks deal additional damage equal to a percentage of damage dealt in a separate attack. She also gains increased movement speed when she hits a champion with the buff active. This ability is also activated on Rakan if he is nearby when Xayah casts the spell.

-E-
Xayah calls back all feathers out on the field, dealing damage to enemies they pass through on the way. If a Champion is hit by more than 3 feathers, they are rooted for 1 second.

-R-
Xayah becomes untargetable for a moment and throws out 5 feathers in a cone, damaging any champions hit.

Essential Knowledge
Xayah's damage actually comes mostly from landing a large E and her W. Her W is actually a huge source of damage late game and should be used when starting a fight for the maximum amount of damage.

Essence Reaver
Essence Reaver allows for spamming of Xayah's abilities without mana issues, and the AD it provides works well with Xayah's scalings

Infinity Edge
Infinity Edge increases crit damage by 25%, which also scales with her E, giving her more damage

Rapid Firecannon
RFC is built to help cope with Xayah's lack of range, giving her that extra little range to get in one last hit or deal damage from safety

Berserker's Greaves
Standard ADC tier 2 shoes

Runann's Hurricane
Runann's Hurricane helps deal more damage in teamfights, furthermore Xayah's W also applies on the split bolts

Guardian Angel
No brainer for assassins that can burst you before you can root them, or to counter "lag" that just so happened to occur when the 1/16/3 Twitch outplayed you

Mercurial Scimitar
QSS is a must have when you find yourself CC chain'd into the next dimension, and helps you escape those risky situations

Bloodthirster
Great sustain and overheal shield

Phantom Dancer
Extra chase, a shield for when you're low, extra crit

Statikk Shiv
Extra burst

Maw
Magic shield that more often than not saves you from a teemo shroom

Last Whisper Item
Armor Penetration for tanks stacking armor or a fed healer

Stormrazor
energized item that synergizes well with statikk and RFC, and provides a slow for the chase potential.

Q-AA-E
A quick root combo,use this if you're starting the fight, or following up on a CC chain.
Q-R-E
lots of damage, and it's good for teamfights where you're looking for the quick combo to sneaking in more damage
Q-W-AA-E
The all in. only use your W once you're in range so you don't waste any of the duration. line up your feathers so your target gets hit by as many as possible for maximum damage.