Buzz
Mid-game, consider substituting Poppy with Shen to enhance durability. Aphelios and any Marksman unit would be a good choice to soften the opponent's front line, creating opportunities for Kassadin to finish off. Moreover, reaching the 3-star milestone with Aphelios and Targon is extremely valuable at this stage.
Once reaching level 7, refrain from purchasing experience and Roll to upgrade Kassadin to 3 stars. Taric and Soraka should also be prioritized to reach the highest level. After achieving this goal, proceed to level 8 and complete the composition with valuable units like K’Sante and Senna.
As for the Legendary choice, Poro would be the optimal selection for this composition as it increases the Void Duo's appearance rate. It's important to note that this composition can only be constructed when the player possesses the Void Duo core. Regarding item choices, Kassadin would require Guardian Angel, Spear of Shojin, and Bloodthirster (or Hand of Justice).
Conclusion
With the power reduction of Legendary Draven, compositions not relying on it such as Kassadin Void Duo are proving to be quite strong. This promises to be a surprising and challenging composition for opponents to counter.
