The Phoenix Chidori is a jutsu created by Gen Nakaido which he taught to Aichi Uchiha. It was once called the Thunder Fire Palm. This jutsu soon became the basis of the Nakaido Clan. This technique usually starts the same way a usual Chidori does, but instead the user channels fire chakra into his or her hand as well as lightning chakra. This attack has the same effects as a normal Chidori as well of the effect or burning the damaged tissue of a wound to slow or prevent healing. This jutsu has the same effects on the user's hand and wrist, making the jutsu hard to control and costly to use.
Normally, the strength of the jutsu is proportioned by the amount of fire chakra over the amount of lightning chakra used. It is also usually, one elemental nature depending on which chakra is used most. However, Sasuke Uchiha was able to combine Fire Release and Lightning Release and equallize them perfectly, making this jutsu fall under the Plasma Release category and making the jutsu the Plasma Release: Chidori.