User blog comment:B214/Talk About What You Want! 3/@comment-7401186-20141104112658/@comment-99.196.4.193-20141105001440

If you remember in vol. 16 Rias almost completely destroyed Grendel while the rest of the team combined were having a hard time against him buying her (Rias) time to power up. I don't think Rias is the weakest in terms of power, but she does have the disadvantage of needing time to ready her attack. But remember Issei needed 2 minutes (if I remember correctly) when he first attained BB and now he doesn't need a warmup period. Who knows what her next power up will be like?