So you know what marks are, you know what the marked are, but how exactly do the marks work? Well, this is where you will find out.
First of all, being marked kind of hurts like a bitch. It feels a little like somebody is burning something into your skin, or tattooing you faster than should be even slightly possible.
Once the experience is done, the marks resemble a black eye on the back of the marked person's dominant hand.
When a marked person uses their power for the first time, their mark changes.
Realized marks who have used their power can have any sort of design to their mark, but they are almost without exception symbolic of something that defines wither the marked person, or their relationship with their powers.
Marks start small, barely two inches across and one inch high, but depending on the amount that the powers are used, and the amount of other marks killed, the mark can expand and change.
There are two types of mark transformation.
Experiential and Conquest
Experiential: Experiential is transformation resulting from consistent power usage and proficiency. Generally this advances the complexity of the design, rather than actually adding to or changing it. Enough of this and the marked may find that they are able to move their mark.
Conquest is what happens when one mark kills another and advances in power as a result. This tends to add to the mark and make it larger, adding new designs to the central one, and expanding it overall.