Hello fellas, heres my fiddle built n i hope u all enjoy it
I love fiddle, he is my main, n i know that he is a pain for enemy team when played properly in rank games, so read all my built n then comment.

Fiddle is a natural ganker, Crowstorm is one of the best skills in the game, the secret is know how and when to use it.

Pros!

Almost every Gank is a kill.
Fear! 3 Secs best CC in the game.
when u are 1 on 1 vs another dps you ussualy win if you fear him and drain him correctly.

Cons!

You are super squishy
Your jungle can be countered easily if u are not carefull (ask team to protect your blue, ward the enemy jungle to steal buffs and gank enemy jungler)
If you dont play correctly you are gonna be the feeder and the focused character every team figth.

ok! here comes the deal
9 greater mark of insigth: you need mp! these 9 + archaic knowledge + sorcery shoes = 23.5 of mp + the passive of fiddle will allow you to deal good damage even on tanks. remember AP is nothing without MP!.

9 Greater seal of replenishment; fiddle is so mana dependant at early game that every time your blue gets off u are mana starving, these runes will help you to take over these mana starving times. in late game you dont need them more, thats why these are flat mana and no per level.

9 Greater Glylph of focus: these are the more important ones, Corwstorm is awsome! so you need to make it as often as possible these runes + sorecery and intelligence will give you 15 % of cooldown reddox as the game starts!

3 Greater Quintissence of potency: to start with 15 ap + amplifying tome = 35 ap to jungle faster.

Classic 9/0/21 for ap DPS and junglers

Amp tome: why these one insted of dornas ring? easy these one gives you more AP and can help you to make later the morello.
Health Pot: to jungle more safely, u can get killed easlily if you are walking half dead all the time
Boots: get you your magicalmagic penetraitong boots! u can feel that you are slow as hell but the mp worth it.

Morello´s Evil Tome:: ok, these is the important part, as ive been repiting all the built, as often u can lunch the crow storm is better, with your masteries, runes and these u get not only the cooldown, but also the mana regen for the late game. Morello is an exelent item becouse gives you a good amount of ap, the cooldown and the mana regen.
After these i like to get my rabbadon to make more damage, deppending of the game.

After these i like to get my rabbadon to make more damage, deppending of the game. Rylai´s is good for teamfigths and gives you lots of hp, the will of the ancients help you to survive if you ever whant to Storm the enemy team and you get focused.

most important: fear and drain.

OOOOOOk
Always fear and drain when you are one on one.
if there are 2 or more enemy champs use dark wind, then fear one and drain the more squishy one.

REMEMBER fear is good for escaping too, if you thing you will probably die, fear and run, i you chased by more than one enemy champ; try always to fear the enemy that has the more important cc (exmple, im being chased by Kat and Veigar, Fear Veigar!)

Crowstorm: you know the basics, get into the grass, jump in with the storm fear and drain the poor ganked guy.
But every time you pick fiddle is normal for the enemy to ward the the grass, so your gank is ruined, thats why you need an oracle to see the wards and jump in more carefully.
Dont be afraid to jump in a tower range to kill a dps, is quite simple, mark the location in the map, and the lanners must help you, you jump, fear and drain, while you are draining you can tank the tower, and the lanners can jump in too, after the enemy champ is dead, flash out. quite simple.