Sorry for being super late, I finally got accepted to the forums and was just checking out some threads, however I noticed this one and wanted to correct something about the barrier. The barrier needing seven human souls to break it is an over exaggeration, and this said many times. Firstly, when Toriel stops Asgore from fighting you, she mentions how all Asgore needed was one human soul and could've crossed the barrier, which Asgore agrees with, and in another route offers to
give you his soul cause he knew that you only needed one human and monster soul. This is consistent with Alphys' statement that to cross the barrier, you need at least ONE human soul, and one monster soul. Meaning that you don't actually need 7 souls, and it's an over exaggeration by Asgore likely via his hatred and rage for the humans. (Also if the quote doesn't work, that's my bad. I don't know how quotes work here yet)
That being said, I think the barrier is likely not 2-B in durability, but probably 9-A considering that's where we have characters like
Asgore and
Frisk who can't break it on their own.