Yone & FiddleSticks Synergy
Yone Top and FiddleSticks Jungle win 54.0% of 1,584 Low Elo games together, +1.6 points vs expected, 2-patch window 26.19-26.20.
Researched on LoL patch 26.20. Tips are written to hold at any rank; stats come from Low Elo ranked games up to patch 26.20.
Playing the duo
Fiddlesticks can fear enemies with damaging spells cast from unseen, sending them fleeing; Yone's Fate Sealed(R) hits along a line and pulls the enemies it catches. Players report that Fiddle's fear can set up a single-target Yone chase, but can also scatter a group before Yone's multi-target R. (Unverified: no source confirms this note.)
How to play as Yone
On a gank, follow Fiddlesticks's Terrify(Q) with Soul Unbound(E) and charged Mortal Steel(Q3) to stay on the fleeing target; hold Fate Sealed(R) if the fear has split several enemies apart. (Unverified: no source confirms this note.)
How to play as FiddleSticks
Before opening with Crowstorm(R) from unseen, coordinate Yone's Fate Sealed(R) follow-up; if your fear sends enemies in different directions, wait until he has a line that still catches the group. (Unverified: no source confirms this note.)
Sources
These notes come from r/YoneMains, r/leagueoflegends, and r/FiddlesticksMains, checked against the champions' abilities.