Suicidal

Heroes who have either attempted to take their own lives or succeeded in taking their own lives, or have been overly eager in the face of death. There can be several different reasons for this, including remorse, "honor", avoiding a worse fate, their lives are terrible, despair, sacrificing oneself for their greater cause/allies, the hero being an insane nihilist, hoping they'll take the villains down with them, or even a redeeming sacrifice and other possible reasons.

Examples of successful suicides include Kerchak (he took a blow from Clayton's gun to save his adopted son, Tarzan), Stoick the Vast (he sacrificed himself to give up his life for his son), Kratos (his suicide was an example of a redeeming one), and Cole MacGrath (he chose to activate RFI to destroy the near-immortal Beast once and for all as well as fulfill his future self Kessler's dead wish, which the RFI's wave of energy not only destroy the Beast, but also kill most Conduit-gene bearer including himself).

However, some of these characters have attempted their sacrifice for their greatest cause, but they were saved by unexpected circumstances: Eren Yeager sacrificed himself to save Armin Arlert at his seemingly dying moment due to his injuries by letting himself devoured by a soulless Titan, but survived when he ended up awakening his Titan Shifting powers, Wreck-It Ralph sacrificed himself by throwing himself down into the volcano to save Sugar Rush and the entire arcade from viruses, but got rescued by Vanellope von Schweetz at the last minute, and Hercules (from Disney) nearly sacrificed his own life to retrieve Megara's soul from the Underworld, but survived by earning his godhood.

Heroes who accidentally killed themselves do not count, as with heroes who only faked their own deaths.