These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Game Breaker: The Blessing Bells in Wayfarer of Time. An item you can get in certain battles and the arena, it will drop a character's level by ten, while maintaining the stats. Crevanille with his third limit and just a couple of blessing bells, that you can get in some battles or chests, will become an unstoppable juggernaut. There is are similar items and gems in other games of the series, but nowhere near as accessible.
Designated Villain : Wolfgang is beloved by his subordinates, and seeks to create a nation for those who are discarded by the current system during times of peace. He also seeks to create a democracy, something so foreign to the world that Hans calls him a genius for thinking of it. He's only a villain because he's at war with the nation Wein is sworn to protect.
Player Punch: The original PS2 version and the entire Original route in Wayfarer of Time are a big series of player punches, with unavoidable deaths, including newly introduced characters and others that you may save in the modified route, lacking some really important info that would have helped avoiding most of those deaths, and finally a bittersweet ending (bordering downer if you didn't do some side quests).