Nyx’s children occupied a heavy percentage of Pandora’s Box. Since they came from a god they’re gods but the myths often refer to them as spirits of whichever concept they personify.
Momus was the spirit of mockery, satire, and unfair blame or criticism. He was not popular among the other gods and his mockery got him banished from Olympus.
According to Aesop’s Fables, Zeus, Poseidon, and Athena were arguing over who could make the very best good thing (because these competitions always go so well). Zeus made man, Athena made homes for men, and Poseidon broke the theme entirely by making a bull. They asked Momus to judge, but Momus is a nitpicky jerk, so he found fault with all the creations. According to Momus the Moron, Bulls should have eyes under their horns so they can aim where they gouge. Men need windows to their hearts. And the home should have been mobile. Infuriated with this condescending manner, the gods in question stopped bickering long enough to throw Momus off the mountain.
In other sources, he mocked Hephaestus for the poor design of the human body, picked on Aphrodite for being chatty (though other sources say Aphrodite is the only being he never found fault with), and he mocked Zeus for…being a womanizing POS (I kind of like Momus for that).
Momus gets mentions all throughout literature. He’s referenced in Plato’s Republic, Swift’s Battle of the Books, Thoreau’s Walden, and Sterne’s Tristram Shandy. I imagine they reference this god in particular to impress with their knowledge of otherwise obscure Greek deities. Well that and satire was kind of their specialty.
Momus also inspired the Knights of Momus, a Mardi Gras society of note.
Also in the box was Apate, the spirit of deception; Philotes, the spirit of affection (though the jury is still out on whether her brand of affection focused more on friendship or sex. Myths contradict where she is concerned); Oizys, the spirit of misery; and Geras, the spirit of old age. It looks like there were a ton of awesome myths about him, but they’ve all been lost to time. Irony.
Nyx also gave birth to a class of vampiric “death-fates” called the Keres. Their kind of like Valkyries only evil. These dark spirits fed off the wounded and dying on battlefields. The wounded weren’t granted a quick merciful death, either. First the soldier’s souls would be ripped free from their body, then spirits would fight over the corpse with gnashing and tearing teeth. Ouch. A few of the stronger Keres got their own names. There’s Anaplekte (quick, painful death); Akhlys (mist of death); Nosos (disease); Ker (destruction); and Stygere (hateful).
That’s the last of Nyx’s children and the end of the box. All that was left inside after all these fun deities escaped was Hope.