What happens if Shen teleports to Nocturne when Nocturne is in midflight using his ultimate?
Solution 1:
Here is an example of Shen teleporting to Nocturne during Nocturne's ultimate.
Shen appears wherever Nocturne was when his ultimate is done channeling. In the video it makes Shen appear in the dragon pit when Nocturne's target was in the river.
Solution 2:
He will appear at the spot nocturne is at the moment if I am not mistaken.