William Blake envisioned organized religion as produced and subsequently passed down to christian believers as a net ensnaring the soul. Instead, he imagined God as imagination freeing the soul from its imprisonment. This is where Orc comes in. He is a rebellious angel that fights for liberty at the fore front of this battle. Blake thought the American revolution was the literal battle in this spiritual confrontation. When slavery was not abolished upon its victory, Blake worried everything was in vain. At least, that is how I am framing his theology in my Wrathful Empathies trilogy.
By Dmitrismirnov – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=28922594