So is Jhin locked into his ult for all 4 shots? or can he cancel early?

My initial thoughts are that he would be able to cancel early, like other people with long ult times like can, such as Wukong or Xerath.

But given the quote that the ult is "situationally the strongest in the game, but might just get him killed" or something like that, I wonder if he's locked into it.