First, a vocab lesson. DEMIURGE -- The term is from Platonic thought, referring to a craftsman or artisan. The Gnostics (heterodox Christians) used the term to distinguish between God the Creator, a malevolent figure who imprisoned souls in a material world and smites them for failing to keep his law, and God the Father, an entirely different being from whom Jesus brought the secrets of salvation.
Now, Pope Saint Pius I.
He was the tenth pope, presiding over the Church during the reigns of Antoninus Pius and Marcus Aurelius. Marcus Aurelius brought the persecution back, so there's some support for the general assertion that Pope Pius was a martyr. I say some support because there's not much to go on.
In truth, there's not much to go on at all. Pope Pius MAY have been the brother of Hermas, the author of the nearly-canonical text, The Shepherd. Hermas identified himself as a freedman, so if Pius was his brother, Pius too MIGHT have been a slave at one time. Pius MIGHT have set the date for the Feast of the Resurrection (Easter) as the first Sunday after the March full moon. Then again, that might have been someone else.
It is certain that Pius strove against the Marcionite heresy, an outgrowth of the Gnostic movement. (I say heresy here because that's how he saw it and why he strove against it.) With the trinitarian monotheism taking shape, there was no room for the dismissal of Yahweh as a demiurge, and thus no room for Marcionites. Of course, from Marcus Aurelius' perspective, there was no room for Pope Pius, either.