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. When possible, I will give an example picture of a character that fits into that tier.
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
Youkai:
Daiyoukai
.
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 = Daiyoukai
Golden Six Pair? (It's unknown what the gold actually does, but Duoluo DOES gain gold when he gets a power-up, so it's related to power 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.)