Ruka-Srp

Ruka-Srp (which means Arm-Sickle in Serbian) is a mutation of a creature called a J'avo (who are subjects who were willingly administered the C-Virus directly into their bloodstream). This mutation occurs when intense trauma or damage has been caused to one or both of their arms.

This mutation is concentrated on one of the arms, where the muscle and bone grow rapidly, beginning from the shoulder joint. As the process starts, existing veins and arteries are severed and then new connections are made leading to some blood loss. From there, the muscles grow rapidly and bones rupture through the skin. The hand mutates the most, bearing little resemblance to it's former state - in its place is a kind of flesh and bone sword with an extremely sharp blade at the end, along with several barbs and spikes surrounding it. If one looks closely, they can see the outer fingers surrounding the base of this new extremity.

In terms of attack, they can swing their arm-blades which have the power to deal severe damage and kill prey easily. They can also jump and charge at their enemies. However their greatest advantage is probably their resilience - they don't appear to have any specific weak points with their mutation. One key disadvantage is that because they no longer have human hands, they cannot use firearms. This means that they would need to close in some distance in order to attack.

It's also possible for a Ruka-Srp to have both of their arms mutated. Interestingly, the mutations remain symmetrical with one another, meaning both arms and weapons are of equal size and weight. It's also possible for the creature to have multiple other J'avo mutations at once.