In both games you sometimes have an NPC with your party, who gives a Game Over if they die in battle. One such NPC in the first game is Professor Alba, who later turns out to be the Big Bad. So... why does this character's death cause a Game Over? My only guess is he survives, but this proves he's holding back his real power, so he murders the entire party for knowing too much?
The player can only sell Sepith. It can never be bought.
Lampshaded and averted in SC. Dalmore opens up a sepith shop in Grancel, noting that he's the first one to start a business like this.
Orbal Factories will make Quartz out of Sepith or open Orbment slots for you if you have the necessary Sepith. For some reason, these services only cost Sepith (and zero money).
It's mentioned that the shops actually overcharge for this service and keep the leftover Sepith, presumably as raw materials for future projects, which is where they earn their "pay" for the services.
Monsters drop Sepith, for some reason.
It's said in-story that monsters eat sepith, so maybe that's why.
Monsters drop cooking ingredients. Some of the drops make sense; many don't.
One of the houses in the ancient floating city near the end of SC has 140 cooking ingredients in chests. These items are 1200 years old.
Guess their food conservation tech must be really advanced.
Star Door 11 in The Third offers a Multiple-Choice Past for Bleublanc, but his hint at the end implies "Con Artist X" is his real identity. This makes a lot of sense given his actions in Cold Steel. Con Artist X fell in love with a noblewoman but was forbidden from courting her due to his social class. Bleublanc in Cold Steel seems to show a great disdain for Erebonia's nobility, and some of his Agent Peacock mannerisms could be seen as satirizing noble stereotypes (something Cold Steel's party comments on upon first meeting him). It's also known that he created a false identity to court this noblewoman. This could be the origin of the "Baron Bleublanc" persona you first see him in in Cold Steel, in which case it's likely Bleublanc isn't his real name. (Which makes sense, as it sounds too flowery for a commoner) Perhaps he became the mask and now uses his first false identity as his "default" one.