The Cybermen from Doctor Who show up in the Fallout universe and must convert all humans and kill all mutants in America.
Cybermen start in Vault 101 with all the residents converted and have a year to gather all the information they can and scout out the immediate area.
Cybermen get comic, book, and audio feats. No time travel. They can also assimilate any technology and weapons they come across.
All factions in Fallout are around and at their peak.
Round 1- Tenth Planet Cybermen
Round 2- Pete's World Cybermen
Round 3- Silver Nemesis Cybermen
Round 4- Nightmare in Silver Cybermen
Round 5- The Flood Cybermen