What's Wrong with Wind Wall, according to (riot champion designer) ZenonTheStoic

He's talking about Kench's shield, but it's the exact same problem. You don't need to anticipate the enemy abilities at all, you just twitch reflex block their most impactful ones.

Q: Tahm Kench's E, "I regret adding the shield on cast begin". I didn't understand this, could you explain?

A: Sure!

Tahm and his enemy are playing a game: Tahm wants to hold off on pressing the E as long as possible, while the enemy wants to hold their big button until after Tahm has pressed and run out of shield. This is a fun game! However, currently Tahm's E does have a cast time (0.25 seconds), but the shield is added in the beginning of that cast time. Meaning the exact moment you press E you get the shield. This reduces the game to a guesstimate of "can the enemy put a CC on me and then kill me before that CC runs out?" If I added the shield at the END of the cast time, like spells normally do, I would extend the game to "can the enemy kill me in the next 0.25s?", which is much richer. It involves making DPS predictions and holding burst spells to the end of your engagement window. Currently, a perfect robot could play Tahm Kench against someone with no hard CC and always turn on the E at the very last moment possible. This is a good sign that your pattern is too simple.