Can someone give me an in-depth explantation of egg moves? I just don't get it -.-
Strictly egg moves isn't really that complicated.
Let's say I want a Chikorita that knows Vine Whip. I have a level 30 male Carnivine that knows Vine Whip. Male VW Carnivine + Female Chikorita (or its evolutions) = Chikorita with Vine Whip.
This works because Carnivine is in the Plant Egg Group. Chikorita is in both Monster and Plant. The parents must be in the same egg group in order for them to breed and pass on egg moves.
Now if I only have a female Carnivine that knows Vine Whip and only male Chikoritas, then I have to do more breeding on the side to get it to work. I'd have to breed Carnivine with a Ditto until I got a male one, then level that male Carnivine up to 11 to learn Vine Whip. I'd also have to breed Chikorita until I got a female Chikorita.
This stands true because it is impossible for the mother (female) of the group to pass on egg moves. Only the father (male) can do so. The mother determines the species. Female VW Carnivine + Male Chikorita = Carnivines.
Chain breeding gets a little more complicated.
A while ago I wanted to breed a female Snorunt that knows Spikes. There aren't any immediate members in Snorunt's egg groups (Fairy/Mineral) that learn Spikes from leveling up. However, Roselia (Fairy/Plant) can learn Spikes by breeding with a Cacnea (Plant/Humanshape). Cacnea learns Spikes at level 33, or I could go find a male one in the wild that knows Spikes.
Male Cacnea/Cacturne with Spikes + Female Roselia = Male Roselia with Spikes
Male Roselia with Spikes + Female Snorunt = Female Snorunt with Spikes
That's a really short chain in terms of egg move breeding though. Some of them can take a lot longer. Once you add in the time it takes to breed for the right gender, especially those with an uneven ratio of male to female, it can take some time. RNG makes it easier to breed the right gender though.