Lawful Neutral Outsiders who Know what you Did.
Outside of the world is a plane known as Mechanus that perfectly sums up the concept of lawful Neutral. On this plane there are creatures that are built with a single target in mind with the purpose of protecting a universal jaw and will pursue that objective at any cost.
Many times they never find their target.
There are six flavours of Inevitables:
Zelekhut – They hunt people who knowingly break laws – Mechanical centaurs with golden wings they use built in spiked chains to snag their target. Will track down those who have commited crimes [No matter how small or petty] and enact justice. If the time is served they simply crumble away. Although if the punishment is death, they will enact that and bugger off.
Now amusingly enough, sticking to loopholes and never directly breaking the law will confound these things to no end.
Kolyarut – Broke a little VOW? smashed a little oath? Humanoid figures made of black metal and armed with rather sharp swords. They willl track folk down until the vow or oath is corrected.
Marut – Those who cheat death. Be it resurrection, necromancy or any manner of fiddling with the natural life span. These are giant constructs made of polished black metal. Really fucking scary and you do not want one of these punching you in the face.
Quarut – Those who cause paradoxes or otherwise fiddle with space and time. Usually tend to hunt wizards. Metallic humanoids made of golden clockwork with hourglasses for a head.
They also hunt for people who break timepieces. Which is where the never leave a clock broken superstition arose from.
Varakhut – Those who would intefer with the intergrity of divinity. Anyone who seeks to become a God will eventually clash. They also seek would be God slayers, but tend not to strike until that path is made clear.
They appear as a vaguely humanoid shaped creature made out of metallic polygons. Knowing full well they won’t be able to attack a would-be-god, they usually go for followers or artifacts of power.
Once someone becomes a God they are now defended as part of the natural order.
Diasut – Those who would alter the nature of realms. Usually in the form of opening gates to other planes. They travel around closing gates when possible. Resmble a giant scorpion… tank… thing with giant gate closing pinchers. Pretty rare to see honestly.