First off I'd like to say, if you're going to try this in ranked 1 of 2 things will happen; 1) you will get alot of hate especially if you screw up 2) Your team will realize how much utility you bring to the table and will play around you. Clearly this is a pick that not many people would make but, I'm bronze, I'm a support main, and I love Fiddlesticks.I picked him up towards the end of season 5 and after getting into the support role I forgot about him, Now I'm doing my very best to make him my most played champion. You're not going to be able to play this role perfectly but as a support you have to keep in mind, people are always going to doubt you and your decision making is the only thing that is going to shut them up about your "troll pick".

"Fiddlesticks has Unique Skills?" Why yes young summoner, I'm glad you asked! Fiddlesticks as a support isn't the ideal pick simply because he isn't seen anymore (and I mean AT ALL). This is what makes hims such a good pick right now. The fact that he is rarely ever played and that his ban rate is almost lower than 0% means that only around 1 in every 100 or so players will understand how to deal with you! That being said let's, dive into this.
Fiddlesticks is a lane bully, the lane bully of lane bullies. You try to farm, , you try to poke, , you wanna start a fight knowing his jungler is top, , , , , and then all he has to do is watch you die slow as he sucks the life out of you with . To make matters worse if the guy gets Lucidity boots on top of he's got about 25% CDR on his summoner spells and can do the whole combo again in give or take 2 minutes!

OH BOY THE BIG PART. I'm gonna enjoy typing this. Get ready for a text wall. When it comes to teamwork as FiddleDiddle support, make sure to use your movement speed buffs to get wards all over the jungle and the river in key locations. So long as you keep wards up and cut down any wards the enemy team has set up against you, you'll always know where they are and they'll never know when they're about to get Fiddle Ulted! Always then most threatening enemy or the best initiator. Always and I do mean always have the first target of your be the enemy mage, that 1.25+ seconds of not being able to ability spam is all the time in the world for your team to delete them. Given you're going to be in the middle of fights almost all the time, don't be afraid to drain the biggest tank on the enemy team after you've pretty much completely disoriented the enemy team. Your will cut their tank down a bit and the absurd damage on your will get them out of the fight real quick. NEVER. EVER. ZHONYA'S. EARLY. Most of the time people will pop the hourglass as soon as they are targeted, this is always a bad idea. Save your hourglass for when you're about to either die or have your back up.

I'm still new to making these guides but, to sum this one up:
You are playing Fiddlesticks
You need to bully early with your E
You Ult whenever possible and make it worth
You never kamikaze without
You will always be that guy that everyone hates and then loves because you did your job
You will always get flame if you screw it up
But, when you make the rest of your team look like a barrel of boosted monkeys, it's so satisfying...