to make Sense how strong which character is i gave them a Self implemented power ranking.
Low class Devils - Low,Mid and high tier
Mid class devil's -Low,Mid and high tier
High Class Devils- Low,Mid and high tier(Kim Jisoo)
Ultimate Class - Low(Venelana Gremory),Mid(Quera), High(Albedo) and peak Tier(Zeoticus Gremory)
Satan Class - Low(Erza Scarlet),Mid(Falbium Asmodeus) High and peak Tier(Serafall Leviathan)
Celestial Class - Low(Ajuka Beelzebub, Hextorias Ceresc Bael, Grayfia Lucifage),Mid(Dragon King Tiamat), High( Sirzechs Lucifer) and peak Tier ( Past 2 Celestial Dragon Emperor's)
God Class - Low,Mid(Shiva), High and peak Tier( Biblical God) {no other Beings are currently in this class only Shiva is Alive}
Absolute Being - Emperor Tier( Nerfed Infinity) and God Emperor Tier(Dragon God infinity, Red Dragon God emperor,Trihexa) Respectively.
[ This is For reference and won't be updated this is till chapter 9 or Mc remains 10 year's old]