The Trinity Seven is a organization hired by Emerada Lugnica.
1000 Years ago when Emerada Lugnica was still alive she ordered to find witch genes of every sin and give it to 7 girls. Those girls would become the Trinity seven and would defend the united kingdom of Lugunica with their life. Though when Emerada died the witch genes were collected, but now Valer Lugnica didn't knew who he should give it. He froze them in a chest in the deepest place in Icathia. When satella was sealed, Flugel chose 7 girls and took the witch genes that Valer froze and gave the girls the witch genes. at that point Regulus Corneas was trying to find Flugel, so immediately after the girls took the witch genes he froze the girls and fled. through now and then all of the girls are unfrozen, Though their status and location is till this day unknown. Some of them are already located and some of them are already living their life and protection Lugunica and Icathia