Death Note's shinigami pair have been illustrated (manga), animated (anime) and brought to life via CGI (live action movies). For the theatrical production of Death Note, I did wonder if audiences would be treated to an awe-inspiring puppet element a la War Horse, or something arty produced with shadows on a light board.
None of the above. For the first time ever, Death Note fans are going to see Ryuk and Rem portrayed live by actors. Cosmetics will create the requisite Death God look.