The Sensei is a Chinese martial arts master who first appeared as the leader of the Society of Assassins, before the introduction of Ra's al Ghul.

After a struggle with Deadman and Rama Kushna, Jonah was destroyed and Sensei regained control of his body.

He next attempted to kill a number of dignitaries by having the League plant explosives along a fault line, stating that using a force of nature to carry out an assassination would be his greatest work of art.

It destroys Sensei due to his impure spirit, but Batman is not only healed, but apparently slightly rejuvenated by his dip in the waters.

His longevity allowed him to learn dozens of martial arts over the centuries, able to beat Batman within minutes, although his age meant that he was unable to physically confront the Dark Knight for long enough to do so.