Black Rebirth of the Phoenix Technique

I was permitted by Kai Maciel, to create this, reference by her Phoenix Rising in FanFiction.Com. So-

This technique is limited to the Shiraha clan, but Itachi Uchiha was able to know about this, and used this technique to Sasuke, when the latter made him young, by losing his maturity. It consumes chakra, depending on the age and the plan to reduce his maturity.