The weirdest thing about the current scenario is that the story went out of its way to tell the reader that this entire fight is pointless.
Even Falling says multiple times that she isn't there to antagonize them, nor would her death mean anything from a narrative perspective.

The only meaningful things that happened were what the Fire Devil said to Denji and Yoru using every weapon in her arsenal at the same time, which implies she's going to need a new one after this.
The fact that both MCs are having a heartfelt moment while being completely oblivious of what is actually happening makes me think something bad will happen.