Vulcan

Along with Mars, Vulcan once held the title of the Empire's strongest before Casshern, Dio, and Leda were born. Wanting to keep that title even in ruin, Mars and Vulcan plot to kill Dio by spreading a rumor that they know Luna's whereabouts; this succeeds in attracting Dio and Leda's attention. Mars and Vulcan battle as a tag-team, with Vulcan using his brawn and giant scythe arm to pummel his opponents.

In their first battle with Dio, Mars and Vulcan win but Mars spares Dio's life at Leda's request. Leda leads Vulcan and Mars to Dio's castle, only to have Dio waiting there to properly handle them. Mars is destroyed by Dio, but Vulcan is not, because Dio knows Vulcan is powerless without Mars by his side. Defeated, Vulcan reveals Luna's whereabouts.

Right after, Braiking Boss appears and Vulcan confronts him about his abandoning the robots. Braiking Boss does not answer, but instead encourages Vulcan to fight him if he's angry. Vulcan hesitates, but then raises his blade to Braiking Boss. He is instantaneously killed.