This begins with the titan Cronos’ mother, Earth, who encourages her children to overthrow their father, Heaven, because out of dislike, he keeps them locked away.

does this look right?

WAY too complicated.

You'd be better off to divide it into two sentences.

Thank you!

You're welcome. Concise and straightforward is always more understandable for your readers.

http://grammar.ccc.commnet.edu/grammar/concise.htm

Based on the information provided, the statement seems to be an accurate summary of the mythological story of Cronos and his siblings. However, it's important to remember that mythology often varies in its details and interpretations, so other versions of the story may exist.