These were the power levels that were set on this fan-fic novel. Actually, these levels were based on the canon level of devil faction:
1) Low class:
a. Two-winged Devil
b. Two-winged Fallen Angel
c. Two-winged Angel
2) Middle class:
a. Four-winged Devil
b. Four-winged Fallen Angel
c. Four-winged Angel
3) High class:
a. Six-winged Devil
b. Six-winged Fallen Angel
c. Six-winged Angel
4) Ultimate class:
a. Eight-winged Devil
b. Eight-winged Fallen Angel
c. Eight-winged Angel
5) Special class: is awarded to those who have appropriate abilities, such as social, political, defense, and business, as well as owned strong influence in a faction.