Burst damage ganks and maximum [R] uptime.
Burst damage and target access
Hitting a champion with 3 separate attacks or abilities in 2s deals bonus adaptive damage.
Gain a burst of Lethality and Magic Penetration after using a dash, leap, blink, teleport, or on leaving stealth.
Collect eyeballs for champion and ward takedowns. Gain permanent AD or AP, Adaptive for each eyeball plus bonus upon collection completion.
Unique champion takedowns grant permanent out of combat MS.
+18 Ability Power or +11 Attack Damage, Adaptive
Gain cooldown reduction and max cooldown reduction on your ultimate. This is increased further each time you use your ultimate, up to a maximum.
Gain 10% CDR when you reach level 10. Excess CDR becomes AP or AD, Adaptive.
Electrocute is Fiddlestick's most reliable form of gank damage and the extra burst allows you to kill your target before your [Q] fear wears off.
Sudden Impact empowers Fiddle's primary fight tool, his [R]. The blink on [R] will grant you a bit of extra Magic Pen for more gank damage.
Eyeball Collection's stacking AP allows you to snowball any small lead you get from ganks in to a huge lead.
Relentless Hunter is the go-to jungle option in this row due to it's ability to help you quickly get to fights and skirmishes anywhere on the map.
Fiddle's kit-defining ability and true threat comes from his [R], so keeping your ult off cooldown as much as possible is incredibly important.
Paired with your item build and Ultimate Hat, Transcendence keeps your [R] on a minimal cooldown in the mid-game so that you're able to threaten ganks far more regularly.
Patch 8.10 saw a buff to Phase Rush and jungle duels for scuttle making Xin a powerhouse.