The Phantom Body Flicker Technique was originally the product of Kagami Uchiha combining genjutsu and the Clone Technique due to insufficient chakra.
If Uchiha Gen could combine the two, making every "phantom" he created a solid shadow clone, and his main body could freely transfer between these shadow clones, then his threat to enemies in battle would be further elevated.
Before long, the scroll for the Multi-Shadow Clone Technique was delivered in front of Uchiha Gen.
This scroll could not be taken out of this secret room; he could only read and memorize this jutsu here within the next day.
So that's how it is. Although there is no essential difference between a shadow clone and the Multi-Shadow Clone Technique, it is equivalent to simultaneously casting multiple shadow clones, which are B-rank ninjutsu, in the exact same instant. This not only requires an extremely massive amount of chakra that can be evenly divided among multiple shadow clones while bearing the consequences brought by chakra depletion, but it also requires my main body's meridians to endure the output of a large amount of chakra while weaving hand signs to cast the jutsu.
And this merely satisfies the requirements for casting this technique. If the amount of chakra is insufficient, then the divided shadow clones won't have much chakra either, and their combat and endurance capabilities will be mediocre. Instead, it will even affect the main body, not to mention the backlash brought to the main body by the massive amount of memories and fatigue that flow back after the shadow clones are dispelled.
If the amount of chakra, physical constitution, and spiritual strength cannot meet the basic conditions, even if this Multi-Shadow Clone Technique is learned, it is merely a flashy trick with extreme danger.
*Without the Sage Body of the