Starting off:
Futaba is about 2x faster than Frieren (Mach 11 vs Mach 20.92), and as we know in the story of Frieren. mages fare extremely badly in close quarters without defensive magic. Futaba would love close quarters while range is not a problem for her, while Frieren's objective here would be fighting at range.
Speed gap also meaning she can close the distance during any instance of downtime. Dodging Zoltraak blasts will also be easier despite the deconstruction due to the speed gap. (From what I remember Frieren usually uses the Demon killing version but she should know the human killing one also? Need frieren supporters to tell me). Especially when you realize Futaba's extrasensory perception means she can sense her malice or killing intent as well as over absurd distances as well as being passive (Frieren needs to activate a spell for it). She's also got insane stealth mastery in case she wants to try going for surprise hit and run blows as well. Stealth mastery that works on those with extrasensory perception like Kyoichiro.
Frieren's flight is completely useless due to the chasm of lifting strength, so Futaba can just point at the ground with Jinpu and knock her down completely. Frieren may as well be fighting someone with gravity powers in this fight. Its even worse if
Futaba pins her down with a continuous Aiki blast like she used against Momo Yozakura.
If the fight lasts long enough then Futaba activates blooming, the fight is over. She gets a sizable strength increase, can blitz people comparable to her base speed (as indicated in her speed justification) and has power null. If we equalize mana and aiki energy, or treat mana as energy in anyway, since Magnanimity is meant to null all forms of attack or energy.
Futaba can do this to Zoltraak or Mana blasts. Futaba also has better stamina feats looking at the profiles too
Frieren's only clear win cons to me are getting lucky with Zoltraak and hitting Futaba in the chest (Where her heart is. so she can't regen) or her sealing, but I don't know how it is activated. However Sealing was used in Frieren's case due to an enemy being too strong, which may be the case here already.
Furthermore I am operating under the assumption Futaba's attack reflection wouldn't work against Zoltraak, if it does then this is just Futaba vs Akai electric boogaloo.
I wouldnt say this is a stomp but this seems like a decisive Futaba victory to me (Like winning 7/10 times) unless someone else has more to add
I will say though that starting distance should probably be bumped up to give Frieren space to make a plan or something
