Strain

are individuals who gained power without receiving it from a king.

Identification
As children, all Strains and humans take a test in kindergarten that evaluates their "Induction Variation Drift", which presumably determines their thinking processes, comparing those of Strains and humans. The test contains questions from illustrations, choosing objects that are out of place in images, and other activities that test basic intelligence and special ability capacity.

The Gold Clan appears to hold the test, and send Clansmen off to observe potential Strains for a set period of time before determining the sort of help, treatment, or detainment needed for the public's protection.

Abilities
The abilities of Strains vary from person to person, and can be incredibly powerful or tame. The more powerful a Strain's ability is, the more likely it is for them to be classified as 'high-risk', such as Anna Kushina or Neko. It is required for Strains to be registered in Scepter 4's database, and detainment may be necessary for Strains who do not comply.