Vasilev was the boss of Crematoria Slam Facility.
When Toombs and his team brought Riddick to Creamatoria, Vasilev only offered 700k for Riddick, as he considered him to be high risk prisoner, and Anatoli Petrov had a bad feeling about him. Toombs suggested that Vasilev show him the real books and make a better offer. Vasilev then gave Toombs couple of days until he comes to a decision. Toombs agreed to wait one day.
When Toombs returned day later, Vasilev offered him 775k, but also revealed him that the Necromongers have followed him. The price wasn't really an offer anymore though as Vasilev and the guards had decided to leave the place already. A firefight broke out between the guards and the mercs. The guards won, and escaped via the tunnels, rigging the door inoperable from the outside.
Anatoli has a bad feeling again in the tunnels and informed Vasilev of it. They then checked on the surface where the saw some escaping prisoners. At the next checkpoint Vasilev and Anatoli prepared for ambush, but Anatoli as killed by Riddick, leaving Vasilev alone in the firefight. Vasilev ordered the hatch to be closed, and prepared to move towards the hangar.
The guards were first to reach the hangar and were pretty sure on their escape, as they opened the hangar door while still loading supplies. To their surprise the Necromongers had reach the planet, and were on the other side of the door. Firefight broke out between them and Vasilev and his men were all killed.
