Eye's of the Empress.

In the Empresses golden palace, the Custodes hold the Blood Game's. In the Blood Game's they test the palaces defence systems and each other's effectiveness. Sometimes they will release an enemy of the Imperium into the palace and hunt them for sport. However if a Custodes is found moving even a millisecond too slow, they are not allowed to be Custodes anymore. They must retire and become Eye's of the Empress.

Eye's of the Empress do not wear armor. At least not the thick golden armor expected of a Custodes. Instead they wear robes and go to live on human colony planets with very few people. There they watch for any threats. Then they signal Terra to tell the Custodes about it. To stop 1 of these signals or to try to decipher their secret codes is punishable by death.

To remain inconspicuous, an Eye's of the Empress may only bring 1 of their lovers with them to these low population colony's. This lover will be given enhancements to be able to pleasure 1 of these god like beings by themselves. However even in the middle of passionate love making they are forever vigilant. Forever watching. Forever ready to alert they're futa sisters of what's coming.