8. Fight The Reaper During Flu Season - Persona 5
If battled conventionally, Persona 5's Reaper is one of the toughest bosses in the entire game, though thankfully also an optional adversary.
But the game's original release came with an amusing exploit to help out embattled players. If you wait to fight the Reaper until the flu season months of November and December, it'll be stricken with Despair and die after just three turns, giving players an easy win.
Unsurprisingly, many players also decided to farm this encounter for major EXP gains, which is certainly preferable to fighting an extremely tough battle against an intensely powerful and resilient foe.
However, for the recent release of the expanded Persona 5 Royal, the flu season exploit was removed entirely, instead inviting brave players to take the Reaper on for real. Or, you know, not.