[Bonzo]

It's simple, every mind connected with a single imperial mind, like a queen bee and the hive.
Charles wanted to use the collective unconscious "God" to format people brains and take the place of Jupiter, or God, call that thing how you want.

It's my theory, but if you think, is more reasonable, a world can be perfect if everybody is without the free will and a single person decide for everything and everybody how you want, then a "perfect world".
This can explain their promise to revive Euphemia, with that way they could pilot suzaku mind and give him the impulse Euphy live again, because to revive a dead person is out of way.
Charles kept Marianne body, but he didn't know again how to revive her....it was a bluff for try to stop Lelouch, or to buy time for ragnarok activation.

V.V plan was a little different, but the final result could be enough similar, the geass cult realizes about 200 geass children, or geass soldier, their duty (when the time was ready) was to take control of every important people, then to control every military, policy, economical movement and to create the "perfect world".
Lelouch destroy everything, then the reserve plan and V.V give his geass to the brother.

However, the anime gived always few or no explanatin about all that stuff, for example, all the children used for to create the geass army...

1)clones obtained by V.V and Charles DNA?

2)children taked in every place (orphans, kidnapped...) and used like experiment prototypes, I used that way in my story for Nonette revenge about her son used for one of those experiment.

3)maybe this was the motivation about the fact Charles had 108 women, children production for that project, then at last, Rolo could to be really a sort of half-brother for Lelouch.
But considering the bigger percentage of geass children had the same age....the third option is the most improbable.