[quote=@Zeal]
What's the Angel Class in relation to Codex ranking?
[/quote]

The general tendency is that Angels are more powerful, but lack the defense.

[quote=@souleaterfan320]
What even are the ranks of codex?
[/quote]

S, A, B, C, D, and F. F is for Codex that can do literally nothing. Baphumet is the only S as of now.