Hear my Evil Overlord Plan:
- Start personality cult and proclaim self as prophet of God or a divine being
- Gather about 3000 followers of my religion (big enough to sustain population)
- Develop ultra deadly virus which spreads really fast
- Develop vaccine against such virus
- Vaccinate self and all devotees against such virus
- Release virus into the wild, effectively killing about 90 % of all humankind on Earth
- Proclaim self as the divine healer and start getting devote followers from the common crowd by healing them (using the vaccine)
- Start new religious culture
Such culture would worship me and my family as the "holy ones," while the first followers of my personality cult would be "the clergy," keeping the literacy and knowledge about the technology. Because I am out of good names, they would be called "The Brotherhood of Steel." (There would be no one to claim copyright infringement, so I would be probably fine here)
Now, the most important: Using the fact that all mankind would drop to "dark ages," I couldn't teach people to read and write, using the knowledge only among "the clergy." Meaning, only members of clergy would be allowed to learn how to read and write. I think I could refuse to teach literacy to almost everyone, because everyone would be too busy rebuilding society. So having no time for school could help me in raising the first generation to be illiterate.
I don't really care about "normal" people dropping back to medieval state of mind, as long as they worship me and my family as the kings (or the Gods).
The question is: How long would such setup be sustainable? How long could my offspring use the fact that I designed such setup? Will humankind eventually go back to the "post-modern era"?