Jojo's openings are the way of doing spoilers right. They're all suuuuuuuper spoilery, but most of them are so obtuse and disguised that you can't even decipher the vast majority of the actual spoilers until you've already seen them for real.
The first two are pretty damn obtuse about it lol. The first opening literally shows the entire plot.
They got a lot better with it part 3 onwards