User blog comment:Crimson and Darkness/Volume 24 discussion blog/@comment-33939194-20171212170618/@comment-2001:E68:6DC0:8600:41B6:CF75:C76C:ED90-20171213023209

In vol 25 against Team Typhone Issei might end up awakening his other powers AxA or ExE

we don't know how powerful excalibur sheath is yet, if it allows xenovia complete mastery of excalibur ruler, that can easily turn the tides in her favour against strada

Also we haven't seen grayfia's true power she is at least at ultimate devil level