This was a really cute introduction chapter to some of the characters and the beginning of the initiation, but there were a few grammatical errors in it. There were parts where sentences were incomplete or had extra parts that could have been cut out.

For instance, when Acqua was explaining where the first years were going to meet, the first part of "she then detailed" could be cut out as it is more just an unnecessary bit and that would make the sentence more grammatically correct.

Another bit is the introduction to Hylia. You start the sentence, then you don't finish it. You're missing the sentence's predicate. What is she doing while Gray and Headmaster Stirling are talking?

When introducing Gray, the sentence "he adds as he fails to notice a person approach him, this person was clearly female..." is actually a run on sentence. A period should be placed between "a person approach him" and "this person was clearly female" to make it two sentences. The next sentence starting with "Dressed in a gray t-shirt" is another incomplete sentence missing its subject.

Some sentence structures are a little awkward as well. "Letting Dust free to run into the light, into a test that was surely going to surprise many." is an example. It feels like the sentence is incomplete; it's like something should be before "letting". A simple way to rewrite this to flow better would be: "Dust is free to run into the light..."

Another thing is punctuation for dialogue. If the dialogue precedes a sentence, then the comma is where the period in the dialogue would be. You guys are really good about this so there no problem there. It's the other way. If the dialogue connects to the part before it, then there is a comma before the dialogue.
Example: John raises an eyebrow at her, "What are you talking about?"

Also, each new speaker dialogue starts a new paragraph.

Other than the grammar stuff, I enjoyed this chapter. The transitions between scenes were pretty well done and the consistency throughout the chapter is really impressive. I couldn't tell it was written by two different authors. Most of the time something has two or more authors, you can pick up on the different authors easily. Even if there are differences, they're really subtle and I didn't notice them.

It's really interesting to see the characters written out as opposed to reading their profiles. So far, you're doing well in writing the characters from what I see and know. Stay solid, guys!