Maria

Maria is a recruitable character that can be found in the abandoned church at Straight Down City, by continue moving right after finding Beatrice's house.

You must give her light scrolls to summon Keila and dark scrolls to summon Phillip. If you keep giving her scrolls, both Keila and Phillip become maxed out. After this, you can recruit Maria herself by just talking with her.

Her quirk in battle is pretty much being a better version of Rachel, since at this point Rachel already left you and can't be recruited anymore.

The game itself describer her as:

"Likes eating scrolls and ass. You shouldn't be able to read this."