Every single Replica that Tristan has created (save for his first Replica, Alaina) has a serial number tattoo’d on the inside of their left fore arm. The Serial is always R-S#-DOB#.

R stands for ‘Replica’. S# is their Sex (01 is Male, 02 is Female). DOB# is the Month and Day of their ‘birth’.

Replicas, as Tristan puts it, is just another fancy word for Clone. However, the difference is that, with Replicas, the person that the DNA is extracted from don’t tend to live much longer.

The reason behind this is suspected to be from how they get the DNA, which is from different parts of the brain in order to have the Replica have the exact same traits as the original. In some cases, different parts of the Cortex are taken in order to keep memories for the new replica (eg. if a dying man wants to ‘live life again’). With all these parts of the brain taken, it is no surprise that the original dies shortly after.

Not only that, but Replicas have a shorter life expectancy than humans, as they are only expected to live about 50-55 years, if the DNA collected is from a human. Replicas created from another replica will live about 10 years less each time, the second replica living about 40-45 years, the third living about 30-35, so on and so forth.

Any efforts to expand the lifespan of the Replicas have resulted in rather bad outcomes such as psychosis and problems with cognitive function, especially if parts of the cortex are taken from the original.