For the sake of Braum's shield? Just watched on Voyboy's stream a Braum block Kathus ult with his E. It was only on his self, but even so. It's a targeted ability.
I'm assuming that if Yasuo were to time it right, he could block the ult with his windwall too.
It's not a projectile. Braum's shield blocks whatever hits him first, as long as it isn't behind his shields or too far to the side of it. Since Braum is literally the source of the Karthus ulti, it is blocked.
Note that this also works for similar things such as Zilean Q, Zed ultimate pop, and Vladimir ultimate pop.
Yasuo could not block it with his windwall because Yasuo's windwall isn't actually part of Yasuo, unlike Braum's shield.
It's not considered a projectile
braum shields his own health too so by doing dmg to him karthus ult first has to break his shield and karthus ult does like 150 dmg - resistence of enemy so clearly it looks like braum blocked the ulti. he doesnt karthus ult was to weak at that moment its kinda like yasuos passive shield
As long as Braum shields in the direction of the attack incoming. In the event of it being a targetted ability, even Deathfire Touch.... the shield must be in the direction of the damage, which means facing the targetted enemy at the time the damage first hits. For Karthus ultimate, Braum has to shield in the direction of Karthus.
Think that is how it goes at least.
