Abilities of Fiddlesticks
Spell skill priority is an important winning factor for Fiddlesticks. Understanding the abilities of Fiddlesticks in League of Legends is another. Below you can find all the relevant information on Fiddlesticks abilities. In order for item builds you should check the build for Fiddlesticks.
Passive: A Harmless Scarecrow
Fiddlesticks' trinket is replaced by scarecrow effigies.
Terrify
Fiddlesticks damaging enemies with spells while unseen or targeting an enemy with Terrify's activation strikes a target unit with fear, causing it to flee in terror for a duration.
Passive: While unseen and out of combat or impersonating an Effigy, damaging an enemy with an ability Fears them for fearduration second(s).
Active: Fear an enemy for fearduration second(s) and deal totalpercenthealthdamage current Health magic damage. If the target has recently been Feared by Fiddlesticks, instead deal totalpercenthealthdamagefeared current Health magic damage.
Bountiful Harvest
Fiddlesticks drains health from nearby enemies, dealing bonus execute damage at the end of the duration.
Fiddlesticks channels and drains the souls of nearby enemies, dealing draindamagecalc magic damage per second for 2 seconds, plus percentfortooltip% missing Health magic damage at the end. Fiddlesticks restores vamppercentage% of damage as Health.
If Fiddlesticks ends the channel without interruption, the remaining Cooldown is reduced by 60%.
Reap
Fiddlesticks slashes an area with its scythe, slowing all enemies hit and silencing enemies hit in the center of the slash.
Fiddlesticks unleashes dark magic, dealing damage magic damage and Slowing by slowamount*-100% for silenceduration seconds. Enemies in the center are also Silenced for the duration.
Crowstorm
A murder of crows flock wildly around Fiddlesticks, dealing damage per second to all enemy units in the area.
Fiddlesticks channels for channeltime seconds, then teleports and unleashes a murder of crows, dealing totaldamage magic damage over duration seconds.
FAQ on Fiddlesticks
What do you max first on Fiddlesticks?
Most Fiddlesticks pros max out 
Bountiful Harvest first.