Click the breeding structure, then click two monsters. Wait for the monster you bred. Click on it once it has bred then wait for it in the nursery. Once it's done in the nursery, click on it and you have a new monster! Then you can start breeding all over again until you have them all. You need 3 monsters to unlock the Kayna. You need 7 monsters to unlock the Theremind. You need 17 monsters to unlock the shop. For breeding and nursery, the timer needs to count up to 100 for it to be done. All monsters take the same time. You will always get a rare or epic
Thanks to mysinginmonsters for the original project