Ps: I'm not gonna repeat power levels of these characters any unless it increases permanently or any character who power level is stated unless in increase permanently or they show transformation that I didn't give a power level too
Issei
(Power level: 400,000)
( power level: 3,999,000 )
(Power Level: 7,999,870)
Rias
( power level: 490,090)
( power level: 2,000,000)
Kiba
( power level: 790,000)
Koneko
( power level: 760,000)
(Power level: 1,400,000)
Xenovia
(Power level: 789,890)
Akeno
(Power level: 470,00)
( power level: 1,799,999)
Asia
(Power level: 205,900)
Vali
( power level: 560,000)
( power level: 7,700,000)
( power level: 10,707,800)