So basically, from what i can see there are a couple issues with this
She insta timestops which he can't resist due to verse equalization not being applicable + BFR being instant death
She can selectively target who to affect (the video she wasn't aiming towards the citizens, rather she was aiming at a god's power that spanned the entire 2 million light years).
We do visibly see humans being sent flying, so it cannot be definitively argued that she intentionally excluded them from the attack. For ordinary civilians in New York, being launched like that would realistically be fatal.
Dreamscape also allows individuals to exit when placed in danger, not exclusively upon death, so escaping it does not inherently prove they actually died.
Again, she was freely able to use her powers because of this
Acheron starts off transformed. Transformed Acheron doesn't engage in sword combat and immediately goes for hax and BFR
Now, because of this, she would not realistically engage in that type of attack while they are around.
CQC is generally the option that makes the most sense for her in that scenario.
Also, the activation method for her BFR requires a slash, which gives Reinhard enough time to immediately go for the kill, especially since the starting distance is only 10 meters, which is well within his range.
She is also a victim to the fact that there is no gap between thought and action for Reinhard, so basically in any given scenario he would always be the one to act first
