Board Thread:Theories and Speculation/@comment-3568954-20170205025300/@comment-734582-20170206091450

AsianReaper wrote: Koto isn't something that doesn't last, really. The effect of Koto is altering a part of someone's mind without them realizing. So even when the technique ends, its effect lasts outside of the jutsu. The lasting effects don't need Koto or Tsukuyomi to sustain it; the effects last by themselves. Exactly. As Itachi ranted on and on about, we make decisions and hold beliefs based upon our own knowledge and perception, our "reality". Kotoamatsukami is a genjutsu that attacks these beliefs and perceptions in such a way that it forces a desirable outcome. But once that belief is held, it can sustain itself since your perception has now changed.

Tsukuyome attacks the exact opposite: perception. It changes the target's perception of time and space, but they're fully aware they're in it.

Together one would have an ultimate genjutsu, but isn't that what Infinite Tsukuyome is? It overrides one's beliefs (nobody in IT seemed aware they were in IT) and one's perception (a personal reality for everyone).