This is a triple carry comp that can play around Akali, Karthus, and/or Viego. This makes rolldowns much more flexible since you can take any of these options (and temporarily play Zed to stabilize), and you can use both AP and AD items for your carries. It's also very easy to play since you can just play the Superfan units the entire game and flex around them.
The Superfan opener is almost necessary, since you need to hold Lillias and Gnars for your board later, and if you don't hold them, you run a high risk of not finding them later. Senna is a great item holder for Karthus, but you can also play around KDA using units like Evelynn, Kaisa, and Seraphine as item holders.
Winning fights is very important with the changes to win/loss streak this patch, so almost always slam any decent items and play strongest board, only play loss streak if you have a good reason from augment.
Add whatever Superfan/KDA/True Damage units as your main core, then tech in things like Big Shot/Rapidfire/Spellweaver depending on your carry. Fill in any frontline traits if you have extra space. Ekko has insane synergy with the Superfan opener, so always play him if possible. You can also play Mordekaiser to make the pivot late game easier.