Here is everything explained.
Circles: Circles are the trials a hellbound must go through to be reborn. There are 7 in total, and each circle will test a different sin and virtue.
Starting sin: Starting sin is the one sin someone committed throughout their life, the most.
Starting virtue: Starting virtue is the one virtue someone has committed throughout their life the most.
Sin ability: Sin ability is granted to someone from their sin. Oftentimes, it is non-combat and comes with a side effect.
Virtue ability: Virtue ability is magic granted to someone from their virtue. Oftentimes, it is combat-related.
Mark: Make a mark on Hellbound's arm that spans a couple of inches. The left side displays their starting virtue; on the right, it shows their starting sin. Somewhere on the line is the corruption ratio.
Corruption ratio. A vertical line on the mark represents how far someone leans into sin or virtue. The lower the corruption number, the stronger their virtue and the stronger their magic.
Shackles: Every time a hellbound commits a sin from one of their marks, immense pain or other side effects come over them.
New sins and new virtues: New sins and virtues are tracked on a separate marking. For example, someone could have a marking of deception and love. While also bearing an separate mark of wrath and forgiveness. Each mark would act separately, meaning if you indulge in deception, your mark of wrath and forgiveness corruption ratio would hardly be affected.