Very few people in Golarion like Hellknights. They may like people who are hell knights but the title Hellknight carries weight and meaning across the regions of the inner sea. The orders of Hellknights began as a vigilante group, got recognized by Chelaxian royalty and then grew into a multitude of orders.
Each group has their own distinctively styled full plate armor and operates independently towards their specific concerns. And what do these orders concern themselves with? The Law, their own law really documented in a collection called “The Measure” which uses 3 primary strictures to encapsulate its philosophy. Called the Chain, these links are Order, Discipline and Mercilessness.
Order in the eyes of the Hellknights is a world so peaceful they have no need to exist where each soul will punish transgressors who hold back progress.
Discipline exists to remind one that achievement comes at a cost which must always be paid. Perfect discipline will pay any cost even beyond destruction of any and every obstacle.
Mercilessness must be upheld as all are guilty, including the Hellknight themselves, and that any compassion is a slippery slope towards anarchy and chaos.
From these philosophical tenants the Seven major orders of Hellknights spun off: Order of the chain, Order of the Gate, Order of the Godclaw, Order of the Nail, Order of the Pyre, Order of the Rack, and Order of the Scourge. While other orders do exist these primary seven are the most well-known.
In Age of Ashes the Order of the Nail is most prominently featured as castle Alterain was one of their first citadels before Queen Domina of Korvosa in Varisia lured the group away from Isger. The Nail seeks to bring order to wilderness. They see roaming monsters, wild superstitions and frontier existence as an existential threat to the concept of society. While many folks would consider monster slaying and scaring away the terrors of the nights admirable work, many live on the frontier to get away from the hustle and bustle of codified city existence.
A Hellknight of the Order of the Nail would slay the dire beast in the morning, lecture against the superstitions of hedge witches in the afternoon then burn down your homestead to build a road between cities in the evening. If you resisted, they would capture or kill you as you are found wanting by the weight of the Measure. If there was any pity or sorrow in the Hellknights heart they would bare down upon their own body with the weight chain to reinforce Order, discipline and mercilessness.
Think Dark Knight meets edge lord meets fascist. That maybe harsh but considering how often Hellknights are antagonists, how the orders use the pits of Hell as an operating model and have some of the coolest plate armor ever dreamed of, it is kind of true.
Are they evil? Not inherently. Psychopaths and murderers generally are not be able to pass the strict enforcement of the codes, but compassion is beaten out of the soul of a Hellknight. You could accomplish good and great deeds, but you will grind many under your heel in the process.
Each of the orders were created in a way to allow Game Masters and players to ask hard and deep questions of their characters. What would you do to bring peace in a world where death can visit you capriciously, then flaunt its power, burn your home and zip away in a blink? How far would you push your body to protect the ones around you? Is any mountain too high? Can you display compassion in the face of a horde of rampaging monsters as the village flees behind you? When the strongest steely will, can be undermined by the rust of petty concerns, why not girdle your soul to prevent the loss of your hard-won strength?
Very few people in Golarion like Hellknights but none can deny they are effective. So what does this mean for the blushing cheeks of our Hellknight fan girl Stenno? Is Demos right in keeping Alak at a distance? Will Alak’s charm butter Bread up? Is there anyone Taffy won’t make friends with?