Author if you manage the maximum story well you have 1000 chapters, recommended manga Shūmatsu no Valkyrie, fullmet, fullmetal alchemist brotherhood, Yū Yū Hakusho and Rurouni Kenshin. To have 1000 more chapters, before finishing the one piece manga because if Rob finishes the one piece manga he finishes the novel, or not, I don't know, author what will you do.