As of now, only canon information is in here. Notably, no explanations will be given to her until explained in the story, as the reasonings, exact power levels, etc, etc will be touched on in the story. This is more of a glossary and a reminder for canonical terms and their order at this point.
Devils:
Low-Class, Mid-Class, High-Class, Ultimate-Class, Satan(Maou)-Class, Transcendant(Super)-Class
Angels:
One Pair of Wings, Two Pair, Three Pair, Four Pair, Five Pair(Seraph-Class), Six Pair(Great Seraph-Class), Six Pair Golden (Archangel)
Fallen Angels:
One Pair of Wings, Two Pair, Three Pair, Four Pair, Five Pair (Cadre), Six Pair (Leader)
Dragons:
Regular Dragon, Dragon King, Heavenly Dragon, Dragon God
Overall Standings
One Pair=Low-Class
Two Pair=Mid-Class=Bog standard most average Dragon
Three Pair=High Class
Four Pair = In between High and Ultimate
Five Pair (Seraph/Cadre) = Ultimate Class
Six Pair(Leader/Four Great Seraph = Satan Class = Dragon King
Golden Six Pair? (It's unknown what the gold actually does, but Duoluo DOES gain gold when he gets a power-up, so it does and represents... something above six pairs.)
Transcendant Class (Sirzechs/Ajuka, Rizevim is kind of a fraud for this tier.) = Heavenly Dragon = Mid-to-lower 'Top 10' (The Top 10 in DxD is the fakest thing ever btw LMAO.)