The Light in Hell, is an event that occurred roughly 10 years ago that resulted in the purification of a 10th of Hell and the absolution of millions of souls tortured there.
Triggered by the untimely death of St. Ávila, and his soul descending to hell, it was said that the compassion and grief he felt for those tormented there released itself in a purifying light that penetrated even the darkest corners of hell.
Akin to a flood, the light spread across the realm, purifying the once unholy land and absolving the sinners trapped, allowing them to ascend back to heaven and earth. So great was the light, that the foulest and most evil of demons there rallied to fight against the purity and return to soul of Avila back to Earth. Thereby preventing the total destruction of Hell.
Since returning to life, St. Avila seeks a way to return to hell and purify the entirety of the dark realm. Hell, aware of his intentions, dispatched the demon Mara to prevent the return of the light and keep Avila's soul at bay.