Searching for Lock in the world of ruins. I knew this was the right dungeon because every other treasure chest was already empty. The real highlight of this arc wasn't just meeting Lock at the end, but finding the one treasure that Lock has been seeking to revive Rachel. The cracked magic stone wasn't good enough for that purpose, but it did allow Lock to hear Rachel's final message.
In more recent years, there was the story of Kirito from Sword Art Online fighting Nicholas the Renegade to gain a magic stone for reviving Sachi, which also didn't work. But Kirito also managed to hear Sachi's final message shortly after. I am sure FF6 wasn't the first to come up with this plot, but maybe it did inspire many people years later.
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