
Xuldarinar |

Every time I get started writing, I jam up on it. I want to do the concept justice, but I simply can't. In short, I want to see made (by one's effort or as a communal effort) a corruption that echoes Elric's dealings with Stormbringer. A closer representation of Stormbringer than wrought with the blade bound magus. Obviously, it can't just steal souls with a mere knick, but.. still it hungers.
I figure to prevent its progression one would need to kill a certain number of Hit Die worth of sentient creatures within a period of time, or it forces the corrupted person to try to kill someone close to them. Corruption Stage 3 forcing them to turn the blade upon themselves. Most manifestations would empower the blade, empower the wielder, give benefits for killing creatures, or some combination.
But thats all I got.

Torbyne |
Are you the PC or the GM in this situation?
If you are the GM talk to the player about it, most people dont pick a class expecting its main class feature to try to kill them and their party all the time. The other players may not like it too much either.
If i was going to make a black blade corrupting a wielder into a plot point i would just use the Black Blade as is, it is intelligent and has a will. It just wants to kill everything though and urges the wielder to use more force than strictly necessary. Its starts off with little repercussions, the sword freely manifests arcane surges or black flames to boost the damage enough to kill, the PC thinks of this as a bonus. in town the party is attacked by thugs with non lethal weapons and the blade not only warns the PC but freely teleports into their hands letting them start killing in the surprise round. eventually stories of the blood thirty nature of the party or just the PC become known. the player has just fallen into the habit of killing everyone they can get away with. then an inquisitor or paladin shows up and shocks everyone when their anti evil powers activate and affect the PC, look at what all the pointless killing did to your alignment! But the PC still feels in control, the sword never had to take direct control to achieve this and the PCs win the fight. Now they get to decide if they want to continue profiting from these little freebies the blade has been giving while also worrying about the costs its influence is having on them.
If they continue to benefit from their black blade knowing that it is pushing them to kill when they maybe shouldnt than the story could progress to the point where the blade is able to manifest as an actual daemon and fight them in an effort to consume their souls. Make that the big boss fight of the campaign. the PC should still have their Black Blade during the fight though since it is kind of why they are a blackblade in the first place. If they kill the daemon than the sword breaks at the same time.
If the Players are aware of the corrupting influence of the blade and try to stop it than they have a new quest to purify the weapon while at the same time it tries to mentally dominate the PCs everynight. If they finish the quest (still fighting an incarnate form of the daemon) than it becomes a gold blade or soemthing instead. the PC gets a an extra goodie for the weapon, a free Good enchantment on it or the like, and they move on.
Dont just make a PC roll to avoid killing their favorite NPC or start party killing out of the blue though.

Torbyne |
Of much greater concern is the humanoids corrupting our brethren. Does anybody have rules for those circumstances?
Take control of the "wielder" and explain to them the dangers of constantly using violence to profit themselves? Extol upon them the use of peace and mediation to resolve conflict.

Xuldarinar |

Are you the PC or the GM in this situation?
If you are the GM talk to the player about it, most people dont pick a class expecting its main class feature to try to kill them and their party all the time. The other players may not like it too much either.
If i was going to make a black blade corrupting a wielder into a plot point i would just use the Black Blade as is, it is intelligent and has a will. It just wants to kill everything though and urges the wielder to use more force than strictly necessary. Its starts off with little repercussions, the sword freely manifests arcane surges or black flames to boost the damage enough to kill, the PC thinks of this as a bonus. in town the party is attacked by thugs with non lethal weapons and the blade not only warns the PC but freely teleports into their hands letting them start killing in the surprise round. eventually stories of the blood thirty nature of the party or just the PC become known. the player has just fallen into the habit of killing everyone they can get away with. then an inquisitor or paladin shows up and shocks everyone when their anti evil powers activate and affect the PC, look at what all the pointless killing did to your alignment! But the PC still feels in control, the sword never had to take direct control to achieve this and the PCs win the fight. Now they get to decide if they want to continue profiting from these little freebies the blade has been giving while also worrying about the costs its influence is having on them.
If they continue to benefit from their black blade knowing that it is pushing them to kill when they maybe shouldnt than the story could progress to the point where the blade is able to manifest as an actual daemon and fight them in an effort to consume their souls. Make that the big boss fight of the campaign. the PC should still have their Black Blade during the fight though since it is kind of why they are a blackblade in the first place. If they kill the daemon than the sword breaks at the same time.
If...
Perhaps I was simply unclear.
1. This is simply a brew I want to see. Might I bring it to the table as a DM or point a DM to it in a future game? Maybe. But this isn't for a campaign currently being run or planned.
2. I don't want to see this done to the archetype. I want to see this as a stand alone corruption. Something that someone who is a member of -any- class could acquire. A paladin hears words of a legendary weapon, thinks they can control it when it comes into their possession and it becomes the instrument of their fall or their new mission to destroy. A fiend presents a ruthless barbarian with a blade that acts as their bloodlust made manifest, only for it to consume them as well when the time comes. A cleric of Szuriel prays for a blade with the hunger of daemons to wage war with and it is answered.
I will say though, your advise is sound otherwise and I appreciate it.

Amanuensis RPG Superstar 2015 Top 8 |

This is basically the same design space. What can a corruption mechanic achieve that the rules for intelligent items could not? Intelligent items already have a mechanic to control and corrupt the wielder (their ego score grows as they gain in power).
Generally speaking, it is easier to design a corruption if you have a clear concept of the thing the corrupted creature turns into (most corruptions in Horror Adventures revolve around turning into a monster). Maybe a modified version of a dullahan or a graveknight tied to a special blade in place of armor? Starting from there, it should be easy to come up with something cool and interesting.