It was the difference between knowing and not knowing. Agurin called the play 20 seconds before while still on red side. He was fully aware of the scenario about to happen. He's moving top side to protect the dive. The ward would've given trynd vision and potentially given karthus reason to pause. In addition, you can't outplay what you can't see. If he sees karthus, he can see when karthus makes his move to dive. Potentially spin over the wall, get behind him in the blue side jungle and turn it into a chase scenario, with brand already progressing towards the play. Buying time, or denial of the dive.
@@artieschmidt3039 it's actually crazy impressive. To see it that far out. To just know, that far ahead of time, and be on the move to intercept. And then, to have it actually happen and play out how you said it was. There's a reason he's the best jungler in the world, and realistically, we're all the tryndamere.