Then a Magic Item might look like this for the GM:

You often have bad dreams, but you manage to live an otherwise normal life. A gulf grows between you and others you hold dear. The burden of what you have seen makes you distant and reserved. You cannot help but always look over your shoulder, moving from place to place. You have a hard time making lasting relationships work. A knock on your door and a mysterious summons takes you into the fold of a secretive order dedicated to combating the Weird, your former comrades included. You spend a lot of time writing about what you have seen, it is a mad compulsion to put into words the terrors you have faced. Your works adopt some of the power of the Weird and become new threats. Madness overtakes you later in life and you spent the rest of your life raving at shadows in an asylum. One night you vanish. Others presume you dead. This is likely the case. The alternatives could be much worse. Rather than continue living day after day with nightmares and the knowledge of what lurks in the dark, you decide to end your own life. You join a cult dedicated to a Weird Power. You must be around others who have seen what you have seen, even if it means worshipping that which you fear. You are shunned from society, pushed out into the wilderness. You live on your own terms, but fear and desperation force you to monstrous acts. Corruption overflows, everyone near you is afflicted by your Weirdness, causing a catastrophic event. Or more. Your humanity is ripped away. The more you tried to resist the terrible urges that the dark left you, but you cannot do so any longer. You become a monster, disappearing off Into the Weird Blue Yonder to enact your new nature.

So what do you think? Should I use Corruption and if so what kind? How would you suggest I best execute this concept? Or is it just better to do away with the idea?

The Bone-Turner's Tale: Reading this book allows you to learn the art of flesh bending.Corruption 0-4: You may reach your hand into someone's flesh to remove or insert a bone. Each time you do this, roll 1d6. On a 1, you gain a Corruption and you must find a new type of bone to insert into yourself before you can reach into anyone else. On a 2, you must find a new type of bone to insert into yourself before you can use this to reach into anyone else.Corruption 5: Bones are no longer enough. You must swallow someone's heart or liver to gain the powers of this level. You may reach in and remove or insert organs into people. Near you, all organs stored outside a body remain healthy andWhenever you use this power, roll 1d6 as before but instead of bones, you require new organs.Corruption 10: Your body becomes bloated, your skill pale. It is evident that you are not fully human any longer. You permanently lose 1d6 Personality. You gain +5HP and you can restore your health by 1d6 by eating the remains of an enemy that you have slain. Each time you do this, roll 1d6. On a 1, gain a Corruption.Corruption 15: Your body is distorted and bloated. Stolen organ pulsate beneath your distended skin. You permanently lose 1d6 Personality. Gain +5HP. You may conjure new appendages and eyes from your person at will. Each new set of limbs gives you another melee attack. Each time you create a new limb, roll 1d6. On a 1 x the number of times you have used this ability today, that limb/eye remains permanently.Corruption 20: You belong to the Flesh now. A tumbling mass of limbs, eyes, and stolen organs you feverishly hunt for more, always more, to arrive at your perfect body. Your character becomes a monstrous NPC.A few things occur to me about this mechanic. What happens when a player discovers this item while they already have high Corruption? It doesn't seem right for them to immediately transform. It would make more sense for this to be on its own track but that runs into the issue of possibly having too many such tracks.Corruption could also be a tool that can effect but doesn't actually track the progress of items, increasing the chance of mutations and the like. It wouldn't solve the problem of tracking multiple items, but it could be interesting.Another idea could be to do Factional Corruption so each item would contribute to a PC's Corruption related to a specific Weird Power. It would make sense then for items take some immediate effect if the PC is already heavily aligned with the Power that the item is related to.So a PC with 5 Flesh Corruption would pick up The Bone-Turner's Tale and find that overnight, the book speaks to them and begins to change them.It would go some way to condensing the number of tracks to manage though it would still be possible to overload on these different flavors of Corruption. This is pretty thematic. It also means that you could combine a status effect like Flesh Rot and its Corruption, such that a supernatural disease that is eating away at your skin can actually turn into a source of power if you find an item or willingly seek out a cult that could induct you into the Flesh's bloody embrace.Another idea could be to scrap the idea of Corruption affecting the progressive influence of items and just leave it as a fairly nebulous measure of how Weird your character has become. It would have some niche uses, but mostly just be a number to look at.One possible use would be to have it effect Retirement. Retirement is usually something where players put aside characters that they feel have completed their task and want to find something else to play. However, in Weird fiction, escape is not always possible.Survivors often find themselves vanishing in the night or becoming embroiled into the Weird themselves, often to the point of transforming into monsters. Others may survive, but find a gulf placed between them and those they hold close, the terrible weight of what they've seen making them hard strange people, haunted by the life they have left behind.So I suppose we could create a chart that would have us roll a die and add our Weird to it.Retirement: Roll 1d6, adding your Corruption.