The reason that Walker checked to see if Fleur wanted to help was simple. Natural mana.
They both could gather it and they both held a lot of it within their bodies. However, Fleur could manipulate it at a much more fine tuned level. Meaning that she would bring more to her and condense it better so that Walker could learn more from the win grimoires.
He didn't even need to explain too much to her since she could sense through their bond the goals he had and what he needed. She had also sensed when his mana was absorbed and knew that the twin grimoires were very unique. Something that stood out from the normal books that Walker had spent hours and hours reading.
Without a single hesitation, Fleur began resonating her mana with Walkers to draw and condense more natural mana together with them. It caused enough of a stir to attract the watchful eyes of a few archivists who wished to witness the unique books found and how they might be able to learn about other ancient books.
