Hunter x Hunter: The Last Mission

The strongest Hunters that once existed in the Hunter Association were split into "light" and "dark", and each walked down their respective paths. The "dark" side begins moving in order to massacre all Hunters! After a brutal attack
Isaac Netero is the chairman of the Hunter Association. Decades ago he sealed away Jed, a Hunter who had mastered the use of On, the dark "shadow" of Nen. Now On users have reappeared at the Heaven's Arena "Battle Olympia" tournament. For Netero, this is the last mission: to protect the Association and the world from a threat driven by hatred and the thirst for revenge. And he's going to need all the help he can get in order to succeed.