Premonition Effect (Bad Omen variant)

The Premonition effect would be the same as bad omen, but instead of given from a potion, it is given randomly. Every tick could have a percentage chance to apply premonition. Or an Oracle of some form could bestow it, to give players some form of guaranteed way to obtain it. Like Bad Omen, it would trigger events from your world. Possibly linked to not just the village but other structures like the Jungle or Desert Temples. The exception is the Trial Chamber. I personally feel bad omen works just fine and another effect would be redundant for the Trial chamber specifically. The Premonition effect could spawn Undead raids or Undead defenses on structures. Such as the temples but potentially the Bastion or Nether Fortress. Blazes though not Undead could be a part of the defense. To extend the list of structures, the Stronghold, Woodland Mansion Mineshaft, and Witches hut could have their own defense encounters. 

Additionally, if we categorize strutures as Hostile, neutral, or Friendly, then only the Village counts as friendly. Perhaps more friendly structures like towns (Larger villages) or Cities (Towns with more compact generation) could be added, making for new event activites. Minecraft presently lacks many events. We have Rain, and Raids. Boss Fights may or may not apply depending on an individuals definition. Please add more events in the future.