Hey, you look familiar! I take a peek in YmtC once in a while.
Let's start with the concept: Alek's character is established very well, and we quickly understand his views on justice and violence, which appear as his two main foci as a character. The initial dialogue, while not groundbreaking, quickly fleshes out the two parties and the clash of "justices", while the short sentence in which the narration casually describes the slaughter of three peasants does a neat amount of work about the violence part. It's a short and very functional piece, showing us the core of the character and the likely source of future conflict in his stories. What follows are observations on details and other smaller concerns.
@Necromancy: A spell that causes necrosis, literal flesh death, looks like necromancy to me. That may be because of my D&D experience, where necromancy includes not just interacting with dead creatures but forcing decay on soul and/or body (enforcing the effect of death) and stealing life (cheating death, though D&D doesn't have the "sangromancy" type), so I didn't have a problem there.
On the other hand, I'm not sure the narrator needs to spell out the schools of magic Alek uses, since as you say the PoV is close enough to him that it shares its values, but that means the narrator probably shouldn't take an aside to tell the reader what kind of magic is being used; I'd see that as more fitting if an external PoV addressed the scene, maybe a narrator close to a character who doesn't know Alek and gets horrified seeing him using necromancy on peasants when he could just subdue them, so the single word would have more impact, representing a revelation/realization.
About formatting: we use the paragraph tag a lot here, and dividing into paragraphs lines makes it easier for the reader to scan the text; when only two parties are speaking, you can also get away with just writing the spoken words of a character without specifying who's saying that because you establish that the speakers alternate their paragraphs, saving words when a dialogue is quick and snappy. Basically, here's what your second paragraph would look like using sad formatting:
Quote:
She turned around and surveyed the crowd behind her, and seeing their numbers gave her gave her a rush of courage. "Mister, our business is with the greedy bastard in there. If you walk away, we'll let you leave here unharmed. Step aside."
Alek did not. The peasant opened her mouth to speak again, but Alek cut her off. "You seek to overthrow your lord."
The peasant spat on the ground. "He's no lord of mine. He's starved us, worked us to the bone, and had his men come and beat us when we protested, all so that he could live his life of indulgent luxury. We've had enough."
"He is your lord, he can do whatever he wishes with you. His word is law, and your station in life is to obey it."
About the quick battle: as I said, I'm not crazy about the narrator taking time to spell out Alek's schools of magic, and the necrotic bolt looks necromantic enough to me anyway. If you want to stress the hieromantic part, you could say instead that Alek's magic turned the peasant's bond of servitude into literal golden chains, or something along those lines.
[tactical nitpicking which only I care about, probably] Other than that, I assumed that the rebel crowd was pretty close to Alek to begin with, so it wouldn't be wise (or even very feasible) casting two spells (who, looking at how many words you use to describe them, take some time to cast - long sentences tend to be related to a slower action rhythm) on a peasant when either one would have took her out of the battle. It makes an example of her, granted, (albeit one than the other peasants don't see because of the rush, which defeats the point a bit) but as self-righteous as Alek is, unless he's also overconfident he should respect the fact that being surrounded by a crowd with pitchforks (read: polearms) is not a good situation for a mounted fighter: there were literal anti-cavalry tactics that involved three infantry surrounding a mounted knight, toppling him with long weapons and then slaughtering him as soon as he fell. The peasants aren't trained, true, but numbers are good advantage to have in such a scenario. All this to say, I'd rather see Alek chain the rebel spokeperson, killing another peasant and the crowd balking when he takes out a third fighter before they can even reach him, then he can trample the two immobilized targets and kill a few others as the peasants flee. If you wanted, you could also make Alek let the chained peasants live as he kills their comrades, then calmly executing them when the others have fled, making the lines about killing just enough rebels to make a point (or to enforce justice, as he'd probably say) dialogue instead of narration.[/tactical nitpicking]
*looks up* I think I may have babbled more words than the original piece has, so it's probably time to wrap this up
All in all a neat, effective piece, with a few aspects that could benefit from a bit of polish. Thanks for sharing!
Edit: I didn't know Robert Frost, but I didn't mind the ending lines.