I want ideas for my mod

I'm making a huge mod called Spirit of Enium along with a few others, and i'd like ideas for it (Link here)

There' s not really any limits, as it contains a lot of bizarre features, as well as many references to outside materials like the games Hollow Knight or Terraria.

The ideas could fit into vanilla, it could not, it doesn't really matter as long as they're realistically accomplishable with a decent knowledge of how MCreator works