I haven't done the villains powerlevels yet so these are there power levels
Cannon Kurogiri
USJ: 35
Stain Arc: 36
Fan-Fiction Kurogiri
USJ: 55
Stain Arc: 57
Kurogiri is by far the weakest in terms of raw power out of all of the villains. The reason for Kurogiri's 20 point power increase is the presence of Samebito, Speaking of which.
Samebito
USJ (Suppressed): 7,000
USJ (Vs Bakugo) 8,000
USJ (If He Wasn't Suppressed): 24,000
Stain Arc: 25,000
Samebito was suppressing his power when fighting both Izuku and Bakugo. He was able to attack Bakugo after fighting Izuku without losing any stamina with a max power level of 25,000 he is almost equal to Stain's power.
Cannon Stain
Stain Arc: 23,000
Fan Fiction Stain
Stain Arc: 27,000
Cannon Shigaraki
USJ: 40,000
Stain: 45,000
Fan Fiction Shigaraki
USJ: 50,000
Stain: 56,000
Shigaraki has a great deal of potential which is why he grew so much in such a short of time. Not only that but he is a symbol to rally on, a symbol of villainy.
If you have any questions about power levels or any inconsistencies please don't hesitate to tell me.