u/AlexanderMugetsu

Basically, any moment where the player is expected to lose due to a high difficulty spike, alongside the story progressing after, but can still be won with general skill or strategy.

1) Vanguard - Demon Souls

The first boss in the game, the player will be way too underleveled and will practically die in one hit, then be revived in the Nexus, to show the player that dying is part of the game. However, beating the boss will allow passage into a short area containing solid early build items, as a reward for beating the difficulty spike. Though they will still be killed shortly after by the Dragon God in a cutscene, it still allows access to a new area.

2) Urizen - Devil May Cry 5

Prologue boss for DMC 5, and also a returning one, beating him either during the first level unlocks the next difficulty mode (and during mission 8) ends the game with a secret joke ending and cuts to the credits, completelty cutting off the main storyline.

3) Haru Urara wins Anima Kinen - Uma Musume

Similar to her real-life counterpart, Haru is never expected to win and for the final run of her Career scenario will having her inevitably lose, as the odds are naturally stacked against her (turf and long tracks are both stats she's poor at) though this is treated as part of her character development in treating her races seriously from then on when she loses, typically she only loves to race for fun. However, with grinding on the Legacy System, it's entirely possible for her to eventually win, and the player to be treated with a special cutscene if she does.