Need Help With “Chapter 2”

Not sure what the fan term is, but I’m at the part where I’m playing as the second character and I’m stuck trying to progress, as this portion of the game is much harder than the rest.

On the first playthrough I was able to advance the story by using Infinity Mode, thus granting me infinite locusts but there doesn’t seem to be an option for this part. I was trying to get through just as Voided, but once I reach a certain point I get a message like “your memories remain sealed” or something and I have to start over. This tells me I have to get this far as unvoided (limited lives) but I keep failing.

Do I have to do this part perfectly with limited lives, or is there another step I’m missing? Please be as spoiler-free as possible, I just need some guidance.