Corruption

Corruption permeates this world, with many characters affected by or studying it.
The dwarves call it 'Black Blood'.

Accepted Facts

• Corruption feels oily/suffocating/filthy to people unused to it.
• Too much (permanent) Corruption turns a person or another living creature into an Abomination
• When this happens their Shadow 'enters their body'. (Source: Dals backstory confirmed with Sam)
• Corruption as an ambient world effect didn't exist when Aglarond, The Glittering Chambers was sealed 1000 years ago. (Source: not mentioned in books or known by survivors. Note that dwarves are also a low magic society)
• Corruption is attracted to some (not all) Cuithger objects as the metal 'thinks it is alive'. The Obelisks and The Moons can be used as 'Corruption sinks' at least in part because of this. The old Empire believed that Cuithger was born of dreams and had been brought by the elves with them from the Dreaming.
• Barktech and prepared mushrooms can also be used as a sort of sink, because of the life in them but can ultimately become full and explode.
• Agata's Soul Stone spell requires a living creatures soul to be trapped in the stone to enable it to be used as a sink. This is why The Orb works as a potential sink. The Stone has a capacity limit, so presumably the Orb does too. (And, terrifyingly, the Moons?)
• Baalmon was able to manipulate it.
• Reginald Thresh aka Abdiel is not a fan, perhaps because it disrupts his society goals.
• The Lake near Ael Nurnan/Stone City of Bardh was excessively corrupted in its depths.
• Both Cuithgar Obelisks we found were already very corrupted (either attracted it or had already been used as sinks by someone else).
• Agata Bosko was studying its effects upon fey.
• Corruption affects casters from other planes as long as they are within ours.

Noted related facts

• The contract on The Tree of Tales said that this world was created to 'define sin and good', and that 'All upon it shall be observed in the ending of their times and their souls measured and tested.' (Theory, was Corruption originally just a measure of sin whose use was amended - D.A.)
• Baalmon stated that Corruption was 'a by product', 'a request' and that 'Mortals simply do not know when to quit.' (session 69)

Causes of Corruption gain in a Shadow

• 'Evil' or 'Sinful' behaviour, eg murder
• Revival of someone from death
• Casting of magic or similar abilities
• Ambient Corruption in an area can affect people who stay in it too long
• Being a Tiefling dooms a person to being more prone to gaining it

Related Abilities

• Shadowsight
• Blood Bonds

Notes from Dalitar's Journal

"14th Cleansing
After much research in the Library I can say with some certainty that most reliable sources seem to point to The Forest of Davokar as either a potential source of Corruption, or certainly a good starting point for research. Unfortunately the Forest also has a track record of consuming unlucky scholars who try to plumb its depths for secrets without sufficent protection or backing, and I have not much of either. Perhaps I should seek out a more sensible research topic."
"16th Cleansing
I tried, I really did, I even sat in with some of Lana's research but Prof. Koldrath's words just kept coming to mind - what's the point in just tagging along with other, better funded researchers when I have a chance to make a difference with my own specialities? So here I am, back in the library, digging through the restricted section again. Did find an interesting journal that mentioned the Forest down the back of a shelf while working off my latest library fine this morning - the start of it seems like something one would expect from an academic journal but the language deteriorates into a strange scrawl as time passes. Perhaps a cipher? May work it out later for some amusement."
"2nd Building
Foolishly agreed to check A---- H---'s shadow as their friends were concerned that they were dangerously close to causing an incident. Should have reported this upwards but Prof. Blackthorn, who usually takes up such requests, is no longer in post. I really should get better at pushing back when socially pressured. Entire thing was a shitshow. AH transformed right in front of my eyes. Terrifying. Fascinating. Unsure we have any records of transformation under Shadowsight that are recent so noting all of this down before I forget. My mind is unsteady from the shock, so unreliable, but I'll try. The Shadow was so dark, like nothing I'd ever seen before. Usually they have some beauty in them, but this one almost made me physically recoil. Upon transformation the Shadow seemed to...enter(?) the body of AH (later notes - verification required but impossible, but this is certainly what I'm sure I saw. Check restricted section later.) and upon entry they transformed. My Shadowsight unfortunately dropped in that instant between the transfer and the transformation, so I am unable to confirm if it remained inside the body of its host."
"3rd Building, 1am
Cannot sleep. Implications of the events of the last day are very curious, and I admit I fixate upon them to avoid thinking about the true horror of it all. Are abominations possessed by Corruption? Does Corruption drive the soul of a person out, killing them, or does it replace it, erasing it? Though I have spent years researching my own Shadow and the theories on them I feel I still couldn't honestly answer if asked what one is. Are the existence of Corruption and of Shadows intertwined? Can one exist without the other? Did Shadows exist outside of our physical bodies before the 'Corruption Event' took place that plunged this world into chaos? I am not going to sleep tonight at all, I can feel it. Bart is looking at me askance. He knows."
"3rd Building, 7am
Feel like shit. I regret everything. Did find some more leads in the Library. Everything points to bloody forest. Need coffee."