In times of duress, the Foundation will recruit individuals from civilian sources or inmates incarcerated of lesser crimes.
During the British colonization of India, the British began documenting and classifying the Indians' lifestyle and traditions, causing the latter to become angry at this and fought back against the colonizers which led to further development of the idea of the Scarlet King.
The Scarlet King is stated to be powerful enough to threaten all of Creation and the Tree of Knowledge itself, making him a multiversal threat if not worse.