There actually weren't many.
Its essential ability was to forcibly drag an enemy into a one-on-one arena that completely favored the Uchiha Clan. As for how much it favored them, never mind that.
In any case, Uchiha Gen was in a wonderful mood.
Although this bizarre Shinobi World had given him another question, the power he gained from awakening his Mangekyō Sharingan had put Uchiha Gen completely at ease.
Now, even if a boss really did camp outside his door, he wouldn't panic in the slightest.
The power Uchiha Gen had just used to crush Ōnoki's Dust Release was precisely the Dōjutsu in his left eye. At the same time... it was also the key that had caused his Fake World to transform.
Dōjutsu-[Night of Mitsu].
It used Eye Power to fully construct the Naruson Domain into a real world entirely under Uchiha Gen's control, then integrated all the power of this world created by the Dōjutsu's wielder into the wielder himself.
Originally, this was merely a Dōjutsu that gave Uchiha Gen raw stats.
But...
Because he had obtained it in advance inside the Fake World, the target of this Dōjutsu's construction had shifted from the Naruson Domain to the Fake World itself.
How big was the Fake World?
In a sense, its boundaries depended entirely on Uchiha Gen's knowledge of the entire Shinobi World and the strength of his own power. In terms of its extent, the moon and numerous other celestial bodies should also have counted as part of the Fake World.
Thus, activating this Dōjutsu had instantly come close to completely draining the Eye Power of Uchiha Gen's newly awakened Mangekyō Sharingan.
Because the Fake World was too vast-so vast that the Eye Power of a single pair of Mangekyō Sharingan could not possibly transform it completely.