Zed ult while rooted

and if not, will there be a lag output so he ults as soon as root is broken if the target is within range

I'm pretty sure Zed's ultimate counts as a movement ability and those are disabled while rooted.

No, since his ult is a dash of sorts, it does not break the root

thanks :)

If he happens to time it as you cast the root, he will dodge it. If he is already rooted tho and he presses ult and you are still in range, he will instantly ult you as soon as the root expires unless the player issues other commands