Commodore Guff from Magic: the Gathering as the librarian.
This is the man who created an entire plane of existence shaped like a giant library, with an entrance on Dominaria, filled with nothing but books, who KNOWS he's a character in a book, and who actually has every book that has ever been printed, is being printed and will ever be printed. Including the books holding the fate of creation.
The only reason why he isn't the most broken bastard in the Planes of Dominaria is because he's a loony old man who's too busy fawning over his books to care about little things like the end of the world. Urza had to bribe him with the only book he hadn't collected yet in order to get him to help against Phyrexia at all...
Also note that Guff was the reason why Phyrexia lost. Originally, Yawgmoth was supposed to WIN, but Guff found the book holding the destiny of Dominaria and discreetly erased some rather... important... parts. Yawgmoth was literally beaten by an old codger with an eraser, not by Urza's convoluted plan. :rofl: