You know, I was recently trying to figure out how egg moves work with the help of Bulbapedia and Veekun's Breeding Chain Finder. However, I am still quite perplexed by them. Would anyone mind explaining? Here is an example of the particular thing that got me confused again.
Sceptile, in the Dragon Egg Group, can learn Leaf Blade. Seviper is also in the Dragon Egg Group. Since Seviper cannot learn Leaf Blade in any other way, it is an Egg Move for Seviper, right? Veekun says no. And despite the Monster Egg Group which Sceptile is part also having members that are in Ground, Seviper nor any other Pokemon I have checked that are in the Ground Egg Group can seem to learn Leaf Blade. Almost every other move I have checked, even somewhat logical ones (A Zangoose with Crunch from a Shinx) are supposedly impossible according to Veekun. Am I missing a key element in the understanding of how Egg Moves work or what their limitations are?