Adding some indian features to Victoria 3
I like this kind of DLCs, as they're totally optional (main features are included in free patches) and they add good content to make a region more interesting to play.
More than "chain of events", what I really enjoy is the "cutomization" of interest groups, ideologies, political movements, class structure, etc., because they improve replayability and the sense that you're playing something different, which are two of the areas where I think Victoria 3's developers have more work to do.