D100 topics for a Lich to write about

I have a prominent Lich in my campaign who goes by Cyde Homi as his pen name and he enjoys writing. He even has a book full of smaller writings of his which have been dubbed by the public ‘the mad ramblings of Cyde Homi’ the only problem is, I can’t really think of much for this Lich to have written about(both logical and somewhat insane, serious and humorous). Give me some writing ideas or book titles for this eccentric Lich to have penned!