I've made a comment about this on one of the YT videos showcasing Fid's new passive.
So far they gave him a new passive, but they also nerfed his Q and W. They cut down the range for Terrify, so now you have to risk in getting close to scare people away. His Drain, in which Riot LOVES to nerf for some reason, this ability will go on cooldown after Drain is done so no more chain-drain.
This is a big problem because this is Fiddlesticks' bread and butter. They've already shortened his tether range down from 700 to 650, but if the ability is on cooldown after it's done, then he's in deep shit. This will make soloing Dragon a lot more difficult, this also goes for every jungle monster. The cooldown for Drain is 10 / 9 / 8 / 7 / 6. Once it goes into cooldown, Fiddle has to wait that long until he's able to use it again.
The new passive is nice, but it only works well with his ultimate, and you won't be able to get to that until he reaches Level 6. Once he used Crowstorm, then it'll go into cooldown and the passive becomes irrelevant until Crowstorm pops up again.
So in conclusion, new passive is only effective with his ult. No more chain-drain with Drain. All you'll have left is a nerfed Terrify and Dark Wind. Once they're all in cooldown, you're defenseless for a while.
And don't forget, Crowstorm is interruptable. If that happens, then Fid's fucked.
I don't understand why Riot loves to buff his Dark Wind when they're nerfing the rest of his kit, especially his Drain.