I have a couple of character concepts floating around my head (one that's been up there for a couple of years, in various incarnations, and one just from the past couple of days).
Both are, in most regards, ordinary magi. However, they both have what could be described as, I guess, some kind of extraordinary Twilight scars likely resulting from a laboratory accident during apprenticeship.
The first, Demios, appears to be a minotaur. He has the body of a man with the head of a bull. He can still talk, eat, drink, do everything as normal. I'm thinking that he (or his master) might have been working on a spell similar to Curse of Circe, a Muto Corpus (Animal) that would have turned a person into a cow.
The other, Griffin, no longer emits visual species (if I'm understanding correctly). Basically, he is completely and permanently invisible. Quite possibly due to a botch involving Perdo Imaginem.
Do these sound even remotely plausible, and if so, what kind of accident or whatever could have caused these to happen?
My first reaction is that Demios happened to irritate a particularly mischeivious faerie, and may now be the object of someone under the effect of a love potion.
Another option: Demios was the apprentice of a Bjornaer magus who was killed in a Wizards War against a Tytalus maga near the end of apprenticeship. The Tytalus took Demios to finish his apprenticeship. Demios' current condition is the result of a particularly nasty exchange with his mistress during which the maga attempted to beat out his Heartbeast Ability, and Demios botched the ability role.
Or: Demios discovered an item of unknown origin which he wished to investigate. The item is a golden calf, with a stylized sunburst between its horns. (Yes, that golden calf!) A curse on the item affected Demios during the investigation, and a quickly sponted but botched defensive spell stopped the curse partway, and turned the calf to slag, preventing further investigation into a way to reverse the effect.
Or: While investigating a labyrinth in a regio, Demios botches a spell and triggers a twilight episode in which he wrestles with a young man carrying a sword and ball of string. Demios fails to comprehend the episode, and emerges with the head of a bull as a twilight scar.
Demios accompanied with a fairie girl and wandered in the forest and made some romantic moves. Once they get aware a bull which made a cow happy.
"I would like to do what that bull makes." Said Demios.
"Really?" asked the fairie girl
Than the girl turned Demios to a bull. "You may go to the cow now."
"Hey, I wanted another way!" cried Demios.
"Oh, you nasty boy!" She smiled and turned Demios into a cow. "I hope the bull reverses some vigor."
"But hey I wanted to do it with you."
"I have never known a human with such a vivid fantasy" Replied the girl, turned herself into a bull and made the angry Demios happy.
After the action Demios shouted "Turn me back into my human form right now!"
"Why?" Asked the fairie girl. "This form suits you far better."
After some demanding, requesting and begging the girl finally agreed to turn him back. She raised her hands and sang some song. Indeed the real bull discovered the new Demios cow and wanted to make her happy, too. While being so excited the bull pushed over the fairie girl stopping the spell. The surprised fairie turned herself into a bird and flew away - forever. And because her hands raised only to Demios's neck his head remained in the form of a cow.
Later Demios found out some cover story with a lab accident but his parens knows his little secret and the fairie girl might reapper again in the story.
I see no problem with the above suggestions. I would go for permanent twilight scarring over fae curse, simply because a fae curse can be lifted, even if it was difficult. Unless you want it lift-able, and then it would be a good option. The twilight episode of the fight in the labyrinth is a really cool concept.
Why to use those boring routines when there are possibilities for far more interesting backgrounds?
Anyway it is just a word telling it cannot be removed. But I like the possibility of removing the curse even better because it might bring another hook in the story and a big change in the life of the character on the long term.
If his body no longer emits visual species, big deal. It's a minor thing.
I'm assuming he still wears visible clothes, and thus looks sort of cool. He might even take the Clumsy flaw to show his lack of spatial awareness ("Where are my hands?" etc.)
Since being permanently invisible is easy enough with items and spells, and the visual of a magus' apparently empty robe wandering around a covenant or tribunal is so cool, I see not major unbalancing there.
Now, if he wanders around invisible and NAKED, ala "The Invisible Man" Griffin, I think he deserves a Reputation as an Eccentric or Perversion that would make his social rolls more difficult. I know if I were speaking with an invisible, naked person I'd be a wee bit put off.