Combo Timing
You repeatedly fumbled the core Zed W-E and W-E-Q sequences in this game, and that cost you several clean kill windows on Ahri and Morgana. The big fix is to slow the combo down instead of trying to make it look flashy: place W first, then walk forward so the enemy burns movement trying to dodge, and only then send the shurikens so you can actually land both hits. In fights, save your R for the moment the target commits or turns onto you, because Zed gets much more value from reacting to their counterplay than from ulting immediately and missing the setup.