I've been creating a series of factions inspired by each class in the D&D book Xanathar's Guide to Everything. Today I reach the warlock, which has two new sub-classes: the Celestial Pact, and the Hexblade. I've already created a holy order last week inspired by the Divine Soul Sorcerer, so let's create a faction made up of spellcasters wielding magic blades.
What if, instead of each member wielding a unique blade, they're all impelled by one central, intelligent weapon that enhances their own? If a weapon can have a will of its own strong enough to influence its wielder, why not one even more powerful one that can affect a whole group?
The Blackblades are a relentlessly efficient group of mercenaries and smugglers operating out of a major port city. Nobody's quite sure how many people are in the gang -- at least half a dozen; maybe twenty. They're a motley bunch who favor dark clothes and one curious harmony: each carries a blade with a dark gray or black blade.
When they spill blood, these blades glow brightly with mystic power, a feature that brings the band no insignificant measure of trouble. It's hard to slip unnoticed past a guard when one's weapon is shining like a torch.
The group is lead by Artemis Giles, an intense, charismatic man in his mid-forties. He wields a massive blade, Foecleaver. He claims to have taken it in battle with the leader of a different gang several years ago.
As a foe faction, unbeknownst to most, Foecleaver actually runs the Blackblades. It's a sentient weapon that desires blood, and in its centuries of slumber it dreamed of clever ways to get what it wants. Instead of simply pushing its wielder to slay the nearest living creature, Foecleaver encourages its wielder to form a band of ne'er-do-wells, figuring they're not only very likely to draw blood, but if its wielder dies in a city the sword will be in somebody else's hands much faster than if its owner dies on a battlefield.
This tactic has worked for years; in fact, this is the fourth gang Foecleaver's run, each one more successful than the last. This new gang grew so prosperous--by smuggler standards--that its power began to "rub off" on other blades in the gang. Within a few years, the gang will be full of Foecleavers, just as intelligent and just as thirsty for blood.
As a friendly faction, Foecleaver runs the Blackblades, but it doesn't thirst for blood; it desires justice. The soldiers of the city paint the Blackblades as ruthless sellswords, but they actually take down slaving operations, smuggle materials needlessly embargoed by greedy merchant guilds, or escort (important) innocents out of war-torn regions.
The group's grown so successful, and Foecleaver's objective so satisfied, that its power has begun to rub off on other blades in the gang.