Dr. Xa.Du is one of the criminals from the Phantom Zone that got reinvented in the New 52 by Grant Morrison. Originally called Xadu, he was imprisoned for his illegal suspended animation experiment. I think currently the go to guy for Kryptonian villains tends to be Zod due to his popularity or just a random guy who is quickly forgotten. But in Grant Morrisons Action Comics we get a transformed Dr. Xa-Du as the Phantom King who sports a cool and creepy form. Greg Pak continues to use him and hope he remains to be used in the future as I think he has been reimagined nicely.
But Superman has many other Kryptonian villains. Out of them, which do you think could be interestingly reimagined? Note, just Kryptonian villains, not regular Superman Rogues from Earth.