The Three Prophets were the first Human-like manufactured Androids that would lead Humanity towards righteousness, hence the name Prophets. Though they aren't based off the Male image and are made completely out of metal and artificial flesh, they were advanced enough to develop personalities on by being surrounded by humans. They have stood their ground for the greater good of humanity and were deployed to settle human-like war disputes, later on they were slowly replaced with the more advanced and more complex Androids known as Nikke's (Humanoid Brains transplanted into Android bodies.) But during this phenomenon they abruptly vanished and was replaced by an Elite group that came after them, known as the Goddess Squad that was led by a Legendary Commander and by their Late leader Lilith. As the raptures have invaded the surface, the prophets have been MIA ever since. They haven't been searched for by anyone, just for the mere reason that the Central Government have wiped all information on them out of all of the Ark's history banks.