In Joker, Fleck's outbursts were triggered when he became angry, embarrassed, shocked or nervous, especially in public situations. Eventually, it's an incident during a PBA episode on a train that sparks Fleck's transformation into Joker and his descent into villainy.
The Joker possesses no superhuman abilities, instead using his expertise in chemical engineering to develop poisonous or lethal concoctions and thematic weaponry, including razor-tipped playing cards, deadly joy buzzers, and acid-spraying lapel flowers.
Excalibur is the legendary sword believed to hold ultimate power, which can only be wielded fully by its true master. Whomever wields this sword will becomes near invincible. However, those who use it and are not destined for it, will be corrupted and ultimately destroyed by an all-consuming lust for power.
The man shot the woman, who was a vendor at Excalibur's concierge desk, then turned the gun on himself, Steiber said. The man died at the scene, and the woman was pronounced dead later at a local hospital.