Hello there folks! Seik and I have spent an unholy amount of time refining our duo setup for 3.19 and let me tell you, it's absolutely nuts. We've tried and failed to league start as a duo back when we were newer player so this is our second go at providing others with the guide we wished we had at the time.
We also wanted to make the most busted build possible between two characters that are optimized for each other. Investing more currency into a build can make anything work, but we prioritized being as cheap as possible in a league start scenario.
We tested tons of different skills and setups for the carry, and Spark Inquisitor turned out to be far and away the best choice. Here's the Spark PoB and accompanying video guide:
https://pobb.in/Xn0FV9un6Do9
https://youtu.be/lq1c2lI4hrE
The Aurabot returns and has been adjusted to compensate for the 3.19 nerfs.
https://pobb.in/BwCqzRjEavED
https://youtu.be/3by90wAKrKA
Along with the well-rounded version of the Spark build, there are 3 different variants for farming Feared/Simulacrums/MF as cheaply as possible.
We've put an enormous amount time and effort into the PoBs, the notes sections have extremely detailed information for leveling and have lots of useful tips. Each passive tree on the builds has an accompanying gear and skill gem set paired with it.
And before you make a mildly self deprecating comment about how you don't have any friends, you should check out the LFG channel on our Discord server. There's a bunch of other people who are looking to league start in a duo with someone and the community has grown to be a friendly and helpful place.
https://discord.gg/gcZKtz7
Hopefully this guide helps you out :)