Naruto kills the council' fics are a whole mood, honestly. They scratch a very specific itch for catharsis after sitting through all the bureaucratic nonsense and unfair treatment he gets in canon. I've found that fanfiction.net, surprisingly, still has a massive archive of them if you dig through the older fics—think stuff from the late 2000s and early 2010s. That was peak era for that trope. The writing can be super edgy sometimes, but you get these raw, visceral moments of rebellion that just feel right.
AO3 has more recent takes, often with better tags so you can filter for exactly what you want. You'll find stories that blend it with other elements, like political intrigue or crossovers, which is cool. The tone on AO3 tends to be a little less 'Naruto goes full murderhobo' and more 'Naruto executes a calculated coup', which I prefer. Wattpad has them too, but the quality is a total dice roll; it's more for a quick, dramatic fix without overthinking prose. SpaceBattles and Sufficient Velocity forums sometimes host rationalist or competence-porn versions of the concept, where the focus is on the logistics of taking down a corrupt system. Those can be fascinating, if a bit dry in the dialogue sometimes.
My personal favorite niche is when the killing isn't just mindless violence but a catalyst for massive world-building changes, like upending the entire shinobi system. You have to sift through a lot of power fantasies to find those gems, though. The trope's popularity definitely shifts depending on which fandom spaces you're in; the older guard on FFN seems more attached to it as a classic form of wish-fulfillment.