Hollowing

No one ceases to exist when they become monsters; they’re still in there somewhere. It just takes some effort to get them out, which is the problem. - Olive Trus

A Dark Place

It is a common belief that once someone falls into darkness, they can never return, no matter how hard someone tries to reach out to them. Such is the case of those who fall victim to the corruption of Gloomification and turn into the monstrous Gloomspawn with only the desire to consume all in their path. This is not entirely true as there is always a chance to do so, as somewhere inside that horror is a person trapped within their own body and unable to do anything to stop when they are doing. This dilemma is officially called a Hollowing, which happens to anyone that goes through a complete Gloomification. From testimonies from those who escaped their dark shackles and reverted to their original state, their recollection of when they were a Gloomspawn is often a jumble of memories and feelings as if they were in a dream-like experience. Often, they could not fully understand what was happening as they were surrounded by darkness that slowly consumed them, and felt empty as they could not wake up from their imprisonment.
This proves that every person who turns into a Gloomspawn is truly gone with a chance of becoming rescued from the self-created prison they have trapped themselves in. This still doesn't make it an easy task to accomplish as it takes a lot of effort to bring someone back as The Gloom's influence has a tight hold on them and won't give up so quickly on the prize it has earned. Of course, there is a time limit for a hollowing when someone turns into a Gloomspawn, as its true goal is to break down any resistance left by a person who has been turned. Stripping away everything that makes them who they are until nothing is left of them as they are consumed by darkness entirely. The process of how long it takes all depends on the will of those who have fallen into this state, which can last for days, weeks, or even months as they resist the fading of the light in them until they finally fade away with only the monster that consumed them being the only thing left.

Returning To The Light

Despite their appearance, deep down, someone is struggling to return to the light in the ocean of darkness surrounding them. All they need is someone to guide them back. - Blazefarer

To bring someone back from their Gloomspawn state, one must be able to remove the Gloom from them so they can fight back against the darkness they created from within. While using enough Radiance can be enough to free someone, a surer way to get them out is to use some Radiance and call out to them and remained them of who they are. By reminding them who they are and the things and the people they cherish, they can break free from the haze they are trapped in. The Gloomspawn that has taken control, is torn apart from within until it is finally destroyed, releasing the person trapped and returning them to themselves once more.