Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
This build is inspired by Drain Ownz by xXBuster, but I added some personal tweaks to the build.
I consider Drain to be the best spell to Fiddlesticks, and the combo you are going for is a Terrify + Drain. This will maximize the damage and keep you somewhat safe.
This is very good for some early harassment.
If you can try and get the mid lain, but play very defensive. Your goal is to level much faster than the other players. Use Clarity to stay longer in the lain.
These runes makes you pretty much OP in early game, and you should be able to at least get one kill in early game, its not an disaster if you don't, but its pretty easy if you time your ultimate at the right moment.