2 things that ruin interesting universes or stories.

Time travel and reincarnation. Once they are inserted into a story or universe nothing matters anymore because no matter how complex something gets eventually the answer is always some form of time travel or reincarnation.

Oh no the young adventurer is stuck in a dark pit with no hope of escape. Good thing he traveled back in time to drop a flashlight and ladder.

Key member of the party sacrifices themselves to save the day while simultaneously dooming them because they are a key member of the party. Boom! I back guys but now I am a lady with a mining hat.

My opinion but it was a real disappointment when they were both introduced as I feel things just lose all sense of order and are just excuses to break the “rules” The creators of a story have made because it’s easy.

I would rather a bland ending that at least was “logical” in the universe it took place in vs the “You never saw that coming” ending that only was unexpected because it should not be possible.