Multiple Shadow Clone Technique (Earth-2356)

This technique is a larger-scale version of the standard Shadow Clone Technique; there is no real difference between them beyond the number of shadow clones being created. Creating even a single shadow clone will require half of a user's midi-chlorians, for which reason the normal Shadow Clone Technique is generally only safe to use for Jedi Masters. Because of how many clones are created with the Multiple Shadow Clone Technique, the midi-chlorian cost is far greater, rendering it unsafe to use for most people other than a Master. For this reason, the First Grand Master declared it forbidden and hid it away in the Scroll of Seals. Anakin Skywalker and Luke Skywalker are among the few exceptions to this rule because of their high midi-chlorian count.

Source

 * https://naruto.fandom.com/wiki/Multiple_Shadow_Clone_Technique