Grey was a little surprised; he hadn't expected to receive a Mythical Grimoire alongside an ancient artefact as a sort of bonus.
Either way, he was a happy camper. Not only could he escort Sophie, but he also now possessed a Mythical Grimoire.
As for other Book Masters attempting to tame such a Grimoire? That was simply impossible. The so-called trials were nothing but a scam.
With a mortal body, no Book Tamer could even hope to succeed. It was practically a guarantee that any Book Master could never tame a Mythical Grimoire.
After all, the limit of a Book Tamer in this world barely reached the level of a high-ranking Book Taming Grandmaster, which, when you think about it, wasn't very impressive at all.