What I found, or rather, the historical figure I found, born in 279 BC, was Sthulabhadra. Now, ordinarily, a Jainist monk would have been the absolutely opposite of what I was looking for. The character who would reside inside him was anything but peaceful, and certainly he does not have any respect for life other than his own, and how the living world might serve his own agenda. And according to wikipedia, Sthulabhadra is not just a Jainist monk, but also considered by some to be "the originator" of Śvētāmbara, because he introduced/permitted the practice of monks covering their mouths with a white cloth, to keep from breathing in small organism, and inadvertently causing their deaths.*
But there was something else mentioned about Sthulabhadra, in every wikipedia article in which he's referred. Sthulabhadra did something not quite right. What exactly he did I haven't yet uncovered -- these are early days yet -- but it seems that somehow, he corrupted the sacred teachings of his faith, the purvas, and used them for something so frowned upon, that his teacher, the monk Bhadrabahu, refused to reveal to him the last four of these sacred concepts, for fear that the teachings would be corrupted and abused. Bhadrabahu refused, knowing that not sharing this knowledge would result in its complete loss.
And that, my friends, is much more like it. Because if there is one thing my character knows how to do, one thing he has mastered, no matter the restrictions placed upon him by the world, it is the corruption of faith for his own ends.
Hello, Sthulabhadra. It seems that you were just what I was looking for, after all.
Related: More Sthulabhadra
*This is in the interest of practicing Ahimsa, which literally means the avoidance of violence, and one thing I DO love about Indian history and religion and mythology is that there are words for everything. It is such a rich tradition and culture, in every respect. That richness, however, is also part of what keeps me away from it -- there is just SO much to learn, and I know that no matter how much research I do, I'm going to miss something important. For which I will just go ahead and apologize now. INDIA, I AM SO SORRY.