An inner hell as eternal as Heaven and Earth. The grip held onto the principles of all creation thoroughly annihilates one’s heart and soul!! The ultimate doujutsu made possible only by Mangekyou Sharingan.
Amidst the insight and hypnosis possessed by Sharingan, is a supreme genjutsu, born from the aforementioned hypnosis: Tsukuyomi. Originally, people on the face of the Earth live bound by limitations like time, gravity, and space; and how people exert their abilities within those restrictions is what separates the victors from the vanquished. But in the mental world where the caster drags their opponent, the Tsukuyomi jutsu gives them control over those very limitations!
Namely, this means inside the genjutsu, the physical world’s common sense is completely irrelevant and opposing the caster is impossible. Somebody caught into the Tsukuyomi find themselves into a strange world of infinity, their fate entirely lying inside the caster’s hands. Some time, they will undergo the torments of Hell, and some other time, they will be repeatedly shown a horrendous, hellish picture of agony and mayhem, with no idea of when either of those will end. As a result, the poor prisoner can only wait until the collapse of their psyches…!! Even a body made of iron or the speed of light are powerless before this jutsu, which is the reason why it is feared as the most powerful.
Sharingan is the Kekkei Genkai of the clan labelled as the most powerful, the Uchiha clan. Even among those who have Sharingan, that jutsu cannot be operated without having Mangekyou, which is its culminating point. Concurrently, the only ones who can defeat Tsukuyomi are Sharingan possessors… And even then, exclusively the elite shinobi who have reached particularly high degrees of skillfulness. Once could say this is truly a God-given jutsu solely allowed to those blessed with Uchiha blood and prodigious aptitudes."
The moment the adversary is exposed to Mangekyou Sharingan, a strange realm as they’ve never seen before extends before their eyes. In there, the world’s principles themselves obey the caster’s beck and call.
Since attacks in the spiritual realm have no power to physically wound or kill, it bestows an unfathomable amount of mental damage.
Only those of Uchiha blood… Does it mean only Sasuke has a chance to break a Tsukuyomi?
The phenomena that happen inside of the mental realm are entirely the cast"
Its is stated to be a "strange world of infinity".
This is cl;early Low 2-C in size as it has it's own seperate space-time that Itachi controls:
bound by limitations like time, gravity, and space; and how people exert their abilities within those restrictions is what separates the victors from the vanquished. But in the mental world where the caster drags their opponent, the Tsukuyomi jutsu gives them control over those very limitations!
Now this would only be for tsukuyomi, but who does this scale to? Well it's pretty simple.
Sasuke, broke out of it, now that alone is just just proof but luckily we have more than that for Sasuke.