The Old One is the living core of Tarrod.
Midian is a dark fantasy game. Most churches in Midian are moral belief structures & guidelines rather than a system that contains a deific figurehead (or many such) and an afterlife.
Context: The gods of Zetacron are physically present in the world. You can go and meet them if you like. Additionally, they are very human, with flaws and quirks—possibly more than regular people.
When the Gods forged Creation they imbued everything with a spirit of its own, a soul so to speak. The trees, the bushes, serpents and birds, everything was imbued with a soul. Even the very earth and the mountains got spirits of their own, as did the winds, the rain and the storms.
Angels are the guardians of Order, the forces that oversee that the purpose of existence is indeed fulfilled.
Demons are the darker emotions, the destructive forces of creation. In primeval times the demons awoke alongside the gods and the angels, and were herded by the greater powers, chased into hell, even as the angels were led into heaven.
The Mad Pope is a wandering mercenary. He is very well deranged as he considers himself to be the pontiff of the dominant faith. His robes are tattered, his mitre has seen better days and there are surely lice in his long ratty beard. What sets him apart from most addle-pated would be holy men is that he has armor under his robes and carries a large crossbow and several one-handed swords. While many would discout him as just another lunatic, for some reason, he inspires others around him and has demonstrated the ability to lay on hands and heal the wounded.