One of the RPG world's first Evil Plans (albeit a very simple one): when Garland reveals, at the end of the game, that he created a time loop by sending the Fiends 2000 years forward so they would send his body back 2000 years to allow him to transform into Chaos, and live forever.
Oh, he doesn't care overmuch about living forever, he wants to kill the Light Warriors forever. After they killed him as Garland, he hates them so much that killing them once just wouldn't be enough. He wants to spend eternity killing them over, and over, and over, and over, and over again. Then, of course, there is the severing of said time loop by the Light Warriors, which also redeems Garland by undoing his original Face–Heel Turn.
The iconic bridge-crossing scene, which signals the real beginning of the game. It's right then and there that it sinks in that the Warriors of Light, having saved a princess, are now out to save the world.
This game's very existence really. A dying company's employee makes one last ditch attempt at a good game. His only real standard: show up Dragon Quest. Instead of one character, choose any combination of four from six unique classes. Instead of less than a dozen boring spells, choose any 24 from at least 36 options. Instead of a handful of equipment, dozens of pieces that match the class options. And, most importantly, do it with an interface and controls that anyone could understand.note Games like Ultima or Wizardry or AD&D Gold Box all had options this robust, but required decent home PCs, hours of manual reading, and/or extensive existing knowledge of the game system in question to actually make any use of these options. And, counting FF1's Japanese release date, Gold Box came after. It doesn't seem like much today, but back then, it was miles above what anyone thought a game could be. It saved a dying company and spawned one of the most famous video game series in the world.