Seal of Solomon

The Seal of Solomon, established by Suleiman bin Daoud, made it so that Others who were bound by it could not harm innocents wantonly. In exchange it provided them with protections as well.

Details

A formal acknowledgement on the part of an Other, that they won’t interfere with mankind without excuse, they’ll obey certain rules, and the practitioners will leave them be. Typically an Other bears some symbol or token of this bargain.  Over time it’s gained a power of its own and being sealed physically alters the Other, but it also affords them certain protections against practitioners.

While most of the older Others are affected by this, many of the newer ones aren't and can act without it interfering with them, however the universe itself conspires to protect the innocent humans as a result. An Other who isn't bound by the seal and also elect to be bound by it to have a greater significance in the scope of things and a power source, but it will open them up to more ways of being sealed and handled as a result.