Sergei

Sergei (Russian: Сергей, otherwise known as Seryoga), is Sasha's uncle who died defending his nephew from the attack on Hole Station.

Overview
The events leading up to Sergei's death are mostly unventured. It is apparent from Sasha's dialogue though that Sasha was visiting Hole from either another nearby station or from a different part of Hole itself and was going to be accompanied back there by Sergei. At least, that was the plan, before the mutants attacked. From the room in which Sergei lies it is evident that there were large numbers of nosalises that attacked him and the others. Sergei's cause of death was most likely caused by bleeding out from a nosalis inflicted bite wound. Sasha mentions that Sergei fought off several nosalises, before being pounced by one (although he managed to kill the mutant).