Well, here is one thing that I do not know if it could work (since Kishin Hishou is not translated, and it's information that may or may not be due to my ignorance).
About the BFR, in theory, the magicians are able to move between dimensions, realities, spaces or time (Kuzaku does it in Kishin, like Another Blood), apart from that they should exist outside the three-dimensional Logic, laws of physics (whether natural or artificial) and concepts of Euclidean Geometry and something else that by nature can interact with beings or places outside the conventional logic and high spaces. IDK if Kurou should have this...
Now about the rest, we must remember that the Magic in Demonbane (Magick / Azathoth Particles) is the ability to manipulate the information that makes up all things (laws, logic, concepts, data, information, dualities, even in extreme cases the origin the same thing), analyze, deface, break, create, manipulate and impose your own on reality itself. and there are some examples of breaking the Spells/Laws/Concepts (
1 ,
2 ) and
Barries/Shields/Armors (This one is in CH2, and realy inexpert scorcerer Kurou and weakened Al), when magicians clash with each other, while at first glance, it seems to be normal physical battles, is in reality, a massive battles taking place on every scale(physically, mentally, spiritually, conceptually and beyond). With both sides try to subjugating their opponent imposing the own law of their World.
And by only his Aura, can kill you and have this feat:
https://imgur.com/7o86ocR
And this is another feat in Etrange Eons (las chapter for Al and Ruri Route):
https://imgur.com/a/lNyAiIN
In CH7 (when all routes start to divides) Kurou Shous some feats like 360ª range of vision (and in later have a range of inifnity, see feat of Strange Eons), and surfive the life absortion of Dagon like Soul/Mind destruction os Cthuluh, Tiberius Vengenful Spirit Bomb and other things, even his own magic can ill himf if he not controll it corretcly (can
erase from existence ).
Personaly, i dont thing she have some way to realy put down Kurou beside the BFR and have bad Regenerationn lol.
Its good (besides i hate the Speed equalized) that the Speed equalized, because personaly, only by feats in Zanma Taisei there are some states that Mages Exist outside/beyond logic, Euclidean Geometry, speed in the Three Dimencional World, even move in places were time not exist, TS, when they perceive that the time were stopped or moved in a void between worlds freely.