Swift is a programming major who was struggling to find work after loosing their old job, until they were offered the opportunity to join an Earth "research," Crew and study the planet as it falls apart. They agreed to it and got stuck doing IT and repair work. They lost a lot of sleep trying to keep the equipment in tip-top shape. Ironically they weren't bothered by Prisma as much as the other associates. She knew and understood Swift was on task and they didn't really get to know each other until much later...
The facility they worked in collapsed due to a mixture of an earthquake and a large creature charging into it and as a result Swift and Prisma were the only survivors. It wasn't long before Veta (who was hunting the creature for resources) found them and explained despite what they were told and seeing there were still plenty of people left behind on earth now thriving in tribes. In fact, there were also other members of research facilities living in said tribes because they lost all means of leaving and getting help for one reason or another.
Swift was of course bothered by and stressed out over this and agreed to help Veta's tribe escape knowing their skills would help the tribe in this mission. With Prisma being more concerned over taking revenge instead of helping others escape, Swift starts growing more and more concerned for her well being as well as feeling an attachment to her
-Their 'fangs' are a body mod they did many years ago in college