Zanka no Tachi, Nishi: Zanjitsu Gokui

is a technique of Genryūsai Shigekuni Yamamoto's Bankai, Zanka no Tachi.

Description
Automatically activated upon the release of Zanka no Tachi, this technique is unseen by the eyes of anyone else unless Yamamoto wills it to be seen. It engulfs Yamamoto's body in heat which reaches a temperature upwards of 15,000,000 degrees. Therefore, it becomes impossible to even touch Yamamoto while he is using his Bankai. The level of heat produced by this technique is so high, it would not actually appear in the form of flames.