Welcome to DC Cinematic Minute, the daily podcast in which we analyze and discuss each film within the DC Cinematic Universe, one individual minute at a time! Currently covering Zack Snyder's Justice League!
Note on the codex. Snyder has said that the skull is a reproduction of that of the first known Kryptonian and the markings represent each major faction of Krypton. It's symbolic more than necessary functional design. And you can see that when Jor-El dissolves it into baby Kal.