These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Complete Monster: King Evrart, hands down. Not only does he refuse to send back his wife back to the Romans, he kills her out of sheer spite before going to his death. By shaving her hair off, making it into a rope, and hanging her with with it.
Mary Tzu: Skantarios' first assessment is reasonable, as he had to spend the very scarce resources available on a small, but highly trained and efficient fighting force, the medieval counterpart of modern paratroopers, to do the job, and he also had to avoid a head-on confrontation with all enemies. However, his campaign of conquest in the Balkans fell away from realism: shipping his troops against the Venetians, when Venice ruled the Mediterranean as the foremost naval power, cutting the Turkish Sultan's empire in the middle while the Sultan stupidly throws away men and supplies against the walls of Constantinople and so on. The strategy relies on Skantarios being the only rational man and all other leaders of the time blind, deaf and dumb.
Moral Event Horizon: Skantarios probably crosses this, but it's unclear when he does. Is it his raid into Egypt? Is it the destruction of Muslim holy sites? Or is it his butchering innocent Italians without a hint of remorse? There are many potential moments to choose from.
Nightmare Fuel: The "personal notes" in Skantarios's diary will send shivers down your spine.
Spoiled by the Format: the outcome of several battles is made clear when the header reads "reports from survivors" instead of the general's name.