They are flat out lying. Machiavellians tend to be manipulative and giving this knowledge away defeats the goals and purpose of machiavellianism.

Like beating someone to death for not believing you're a pacifist.

Edit: See my other posts for a better take on what's going on here.

Do people unironically say that about themselves? That’s really weird.

Attention-seeking. An edgelord, basically.

If they're actually serious, they might be saying it to inure you to the future bad behavior they wish to exhibit.

Either way, doesn't sound like a pleasant acquaintance.

Cringe edgelord. Or just a delusional idiot.

Because of the evil implied in machiavellianism, I'm sure they have plenty of unsavory behavior they would love to see your reaction to.

True Machiavellian character would not disclose it if they are aware of it.

Move on, ignore and, if possible, block.

Uh... it was like the default example for "evil leader" before Hitler.

Sounds like someone who wants attention. Enjoys the edginess and obvious absurdity in a statement like that.

That they take themselves WAY too seriously and they're trying to get whoever's listening to think that way as well.

they are probably a shitty person.

Sociopath, most likely.

Cringe

I would guess that they know either much less, or much more than I do about Machiavelli, or they're speaking ironically. I'd be curious to engage them in conversation to find out which might be the case.

"What? What country is that? Never heard of it."

(I'm gonna "Sir, this is a Wendy's" the heck out of them)

Probably really young and haven't experienced getting burned by such a person before.

They send catty text messages after four glasses of wine to their friends to complain about their kids’ third grade teacher and think they’re being manipulative.

Republican Machiavelli? Or deliberately giving terrible advice to princes Machiavelli?

Either way he really hated mercenaries.

Without context and tone, no idea.

Probably exerts a lot of energy fitting into their idea of who they should be compared to others.

Run

More to many comments: why does manipulative need to be bad, or negative?

The main trigger is a lack of attention from parents in childhood leading to a lack of emotional depth. Such a person may overcome that lack of emotional depth, or emotional intelligence, with logical empathy. I feel like people are way too dichotomous here about something that is far more complex in spectrum. Why hate on people for what amounts to their upbringing. Measure people by their actions. The ability to manipulate, is not itself a negative act. It is in fact a philosopher.

They're probably neurodivergent.