https://writershelpingwriters.net/2023/05/adversarial-conflict-who-is-making-trouble-in-your-story/
This is a great article on all the different types of antagonists but there is one missing.
The ex, as in ex-lover, ex-spouse, ex-partner. Just ask Adelaide (from The Vitruvian Mask). Her ex Henri is most definitely an antagonist.
The ex is even more of an antagonist when there are children involved. 😝
BJ Sikes, author 