My brothers are on board now too! I got them into it on Christmas. We decided to use the rainbow bookmarks if they match the books cover, which means you hatched a shiny. Kind of weird, since every Pagémon is unique, but still lots of fun haha. The youngest one exclusively reads long manga series, so we already know he will have a 5× 48hp army. The older one wants to come up with mega evolutions to beat the little one and he wants to draw his Pagémon, once it's maxed out. I have zero talent so I have only drawn habitats for the Pagémon so far. :D
Sorry for the long comment, just wanted to let you know you inspired some people with your idea and that were having fun. :3
Edit: It's also been great to keep going and give a book a real chance before quitting, which is far too easy with a library card. While I still much prefer E-books I find myself reaching for a physical book more often which is great, since they're supposed to like, be better for your brain health or whatever.