From Exalted - Unofficial Wiki
When an artifact made out of one of the Four Magical Materials of Creation stays attuned to an Infernal's anima long enough (one week for rating 2, a month for 3, a season for 4, a full year for rating 5; ST fiat for N/A), it becomes Tainted, resonating with the foul energies of Malfeas as well as the clean forces of the world. As though it were covered with an oil slick, the artifact's radiance is dirtied and blurred.
The Taint changes the appearance of the Magical Materials it affects: orichalcum blossoms into lacy, eldritch verdigris; moonsilver tarnishes, and it bubbles and writhes of its own accord; starmetal rarefies into strange crystal that reflects light offensively, refracting it through strange noneuclidean curves. The five colors of jade take on the aspect of the worst of their element: red jade flickers with the Green Sun's light; black is unfathomable with toxic, dizzying depths; white crumbles and scours like desert sand; green grows out of control, like kudzu or devouring fungus; blue jade darkens with noxious smoke.
Infernals can attune a Tainted Artifact at its base cost, and non-Infernals must add the artifact's base attunement cost again to gain access to its materials bonus, so Tainted Orichalcum costs Solars 2*base to attune, and Lunars pay 3*base, since they are already being surcharged for not being Solars. However, attuning a Tainted Artifact is not dangerous unless attuning its untainted version would be.
Regarding Magical Materials, I would suggest having Infernals use the normal ones. The source material suggests that the one thing the Infernal Exalted are good at is not letting other people know they're Infernal Exalted. Having weapons that look like melted skin or orichalcum that's glowing with evil light would make that a bit difficult. -stephenls (rpgnet user)
That's a good point, and it might make me rethink my stance on Infernals and the 5MM (as I see it, their animas interact very poorly with soulsteel, and cause the other materials to slowly become 'tainted' and very weird: very old Infernals carry around swords made of verdigris, fungus, poison, smoke...); if they're very good at concealing themselves they might get a Night-like anima privilege (or maybe a Charm or three) that lets them fake anima banners far more easily than the Sidereals can. - FourWillowsWeeping
I'm not sure that I agree with these ideas. I think the verdigris or fungus concept is more an Abyssal thing than an Infernal. It smacks of entropy, not alien concepts, and entropy is the domain of the Malfeans. I think the Infernal should be slanted more toward degenerative changes, both physical and mental, insanity, and bizarre insights. Quick paths to enormous power at huge personal costs. Sorta Cthulian horror and madness. Plus a lot of pain and suffering for the sake of pain and suffering. - doppelganger (rpgnet user)
I'm not uncomfortable with letting Malfeans and Yozis step on each other's toes a bit, but there's a purpose behind my imagery. Abyssals don't, in my world, get fungus and verdigris effects; they get blood, bone, blue flames, rust, darkness. They aren't agents of Entropy, they're agents of Oblivion. Verdigris is - significantly - green. Fungus is alive. The point here is painful transformation into something alien and inimical, not decay. Their Charms do this kind of thing too - I envision an Infernal stabbing orichalcum needles into his eyes to transform his anima into that of a Solar, or replacing his fingernails with long jade plates to seem Dragon-Bllooded. Chthulhian horror is hard to pull off, and it's the ideal, but really how many Infernals have orbs of upsetting light (borrowed from SHE WHO LIVES IN HER NAME) floating around their heads, or have dipped a hand in tainted moonsilver so they can twist it through space, attacking from between moments or out of the shadow of a word? - FourWillowsWeeping
Infernals may not have a Magical Material in the usual sense, but they should have access to all sorts of weird Yozi substances, like the green metal of Malfeas' sun. - Quendalon
I'd actually suggest brass or bronze- I dunno why, but both metals are strongly associated with the Yozi's in my head. - DariusSolluman
My thought is that they have access to the weird 'Malfeas Taint' that, like an oil slick, covers any artifacts that spend too much time in their anima. The Taint makes weird things out of the 4MM, and is wholly incompatible with soulsteel; it turns orichalcum into insane fractal verdigris, makes moonsilver tarnish, bubble and roil unsettlingly, rarefies starmetal into a material made of offensive light and noneuclidean refraction, that shines with incomprehensible colours, and makes jade into the essence of its elemental impurity. Red jade flickers with the Green Sun's light, black is unfathomable with toxic, dizzying depths, white crumbles and scours like desert sand, green grows out of control, like kudzu or devouring fungus, blue jade darkens with noxious smoke. The Taint, which takes some time to develop, makes the material inimical to Exalts of its usual type (is agg a little too dramatic here?), and makes them double the cost to attune it. How's that sound? - FourWillowsWeeping
Hm. I like the idea of the 5MM having alternate effects when attuned with Demonic Essence (Yes, Agg is too dramatic here. *shudder*) However, maybe let the changes be purely cosmetic- the actual magical effect doesn't change. Then, let the Infernal Exalted Material be halfway to anything- double the cost to attune to anything, but they don't have the explosion chance.
This has the benefits of being simple and easy, and the side benefit of pissing off everyone by corrupting their sacred metal :) - DariusSolluman
Very nice. Have I mentioned that your work is reminiscent of Rebecca Borgstrom's? - Quendalon
As Rebecca would say, Quen, "Thank you for your kind words." She's a big influence on me; the resemblance is at least partly deliberate. Consider the Taint thing official - I'll move it up. - FourWillowsWeeping
I'm making an Infernal for an Exalted tournament game to test drive one ^^. However, I need some artifacts for him to use. He has 5 dots to use, any ideas for a cool Melee weapon or awesome armor? ~Overshee