Now with this build the spell vamp is key in it, this way your ulti heals you at the same time. Now i know this isnt a perfect build but it gets the job done, but the only thing u want to do is to build magic resit until your health is increased. Now you can baron at lvl 16 but u will need to use your ulti on him and silence him when u can but the fear doesnt work on him so dont waste your mana on that, and to make it even easier for you get the blue buff and also the blue elixer from the shop to really destroy him quickly and no one will expect for fiddle to go baron at suck a low lvl so it will give your team a great advantage.