No, the ring had not been forged by the Borgia family...but it had been the request of Lucrezia as a clever way of disposing of a rather insistant and boorish suitor.
Firenze, Italy 1501
"You've already been wed twice, Lu. Do you not think that this man may yet indeed be your lifelong husband?" She snorted in contempt. "That, that...MAN would see me tied down and shackled - at the mercy of his very whims. I need to be rid of him, somehow. And too much suspicion has been raised regarding the death of Alfonso."
The alchemist raised an eyebrow at this. He'd provided the hemlock and aconite that put her second husband in the grave, and while there had been no proof of the cause of death, he had to agree that a third tragic end would spell doom to their little games they played.
Carlo knew of a potential solution, one that would get rid of the obnoxious and domineering Nicolo while eliminating any suspicion toward his young friend. But the solution...no, this could warp reality beyond repair. Still, she was a dear friend, perhaps if it was used only once or twice?
"Lucrezia," asked Carlo. "Lucrezia, I think I may have a solution...but I need a man's ring."
"You shall have it," she declared. "But by no means tell me your plans. The less I know, I think, the better off we both will be."
And so it began. Lucretia delivered the ring to the agreed upon location by the crooked root of the tall linden tree. Carlo recovered it and began his crafting.
There was not a great deal of actual labor, merely a softening of the gold-plated iron, the implantation of an Egyptian scarab into the base of the bezel, and the small canine face in the collet.
The actual spell, however, was arduous. Dealing with the darkest arts usually is, and the deliberate killing of the puppy for fresh blood saddened Carlo. But it was required for the desired effect. More dangerous was the setting of the incantation. It would have to be recited during the engraving of the inscription, and the ring must be worn while doing so - and then be immediately removed as the inscription is completed. A mistake could trigger vast amounts of energy, energy that could permanently ensnare the caster.
But Carlo had mastered this sort of magic, if at a less advanced level. As he intoned "In Canis Corpore Transmuto," he completed the cut, shaking the ring from his hand as he did so. The ring pulsed and glowed with an unearthly greenish light for several moments, then faded, leaving what appeared to be an normal if interestingly crafted golden ring. With pride, Carlo picked it up, and wrapped it for his young prodigy.
"It's quite beautiful, Carlo. But I hope you weren't expecting me to offer it to that brute, were you?
"I was indeed, my dear Lucrezia. I think you'll be satisfied with the results if you do. Observe the incription on the upper shank." She did so, reading "In ca-"
Carlo immediately placed his fingers over the woman's lips. "See that you don't, dear, the spell is quite powerful...and irreversable."
Her eyes widened. "But what does it do?" Carlo smiled grimly.
"Any man, any person, who reads the inscription while wearing the ring will lose his human form forever. Whatever dog he has most recently come in contact with, or the canine that is closet to him is what he'll become. You need only place the ring in his possession, and let his curiosity do the rest."
"How is such a thing possible?"
"With the Dark Prince, very little is beyond possibility...though I expect you know the ultimate price of such trafficking."
Lucretia Borgia knew, but if she was concerned, she payed it no mind. If a bargain with Old Nick was required to rid herself of Niccolo, then so be it.