Complete Monster: Quintus Servilius Caepio starts by stealing a fortune in gold that legally belonged to Rome, having several hundred Roman troops murdered by bandits to conceal the identity of the thief. Then he causes the worst military disaster in Roman history because, coming from an immensely aristocratic background, he considers himself above working with the lowborn consul appointed to fight a massive barbarian invasion. Caepio survives the battle by stealing a boat and abandoning his entire army to their deaths.
Evil Matriarch: Servilia to Brutus. Servilia may be the most ambitious character in the series and Brutus is rather...mediocre, to be kind. She does a lot of despicable things so she and Brutus advance in Rome. And she's also just kinda cruel.
Fridge Brilliance: If you get annoyed at the depiction of Gaius Julius Caesar, you might eventually realise that the story has been written in the form of propaganda written by Augustus. It was entirely in his advantage to present Caesar as awesome, and depict all of his enemies as bickering petty men.
Sulla discussing a potential Arranged Marriage for his daughter Cornelia, during which it becomes clear that Metellus "Piglet" Pius has been paying much closer attention than he has.
Mamercus: It all depends. What color are her eyes? Sulla: I don't know. Metellus: A beautiful brilliant blue. Mamercus: What color is her hair? Sulla: Red—brown—auburn? I don't know. Metellus: It's the color of the sky after the sun has just disappeared. Mamercus: Is she tall? Sulla: I don't know. Metellus: She'd come to the tip of your nose. Mamercus: What sort of skin does she have? Sulla: I don't know. Metellus: Like a creamy-white flower with six little gold freckles across her nose. (beat) Sulla: Sounds like you want to marry her, Quintus Caecilius.
How Cato persuades his former father-in-law, the gourmand Philippus, to give his blessing to remarrying his daughter. First he offers him the lion's share of the wine cellar Hortensius left him in his will, full of fabulous vintages... and then he threatens to smash every single amphora with a hammer.
The sister/wife of Mithridates hands him a cup of poisoned wine. He chugs half the cup, then cheerfully identifies the poison she used and tells the court that she couldn't have chosen better. Then he makes her drink it.
Porcia's suicide from swallowing hot coals was bad enough without the further suggestion that it was actually how Servilia murdered her.
The Serious Business reactions to the violation of Bona Dea's rites — including mass abortions, infants left to die, and the implied Human Sacrifice of the slave girl who let Clodius into the house.
Squick: Cleopatra reflecting on sex with Marc Antony, specifically in reference to the size of his manhood, and how "he would have hurt her, had she not given birth to Caesarion." Think about it.
Tear Jerker: Plenty: A lot of sympathetic characters die young or violently. Cato's crossing the Libyan desert (and seeing visions of his long dead brother and mother, both of whose fates are very sad in themselves) is very moving.
