Page 65537

Page 66537 is the final monster to attack Luka in the San Ilia library. With incredibly high stamina and a variety of techniques, Page 66537 is much more dangerous than the other two monsters fought beforehand, Page 17 and Page 253.

Unable to be sealed by normal means, she has to be defeated with a fire attack. When Luka drops her HP to 0, Alice conviniently manages to set the library on fire by not cooking her potato properly. This manages to finally seal Page 66537, ironically allowing Luka to grab the book Alice sent Page 66537 to protect.