is adopted by Jor-El and Lara as their son, Kal-El, eventually discovering an Oan power ring. In Superman: Secret Identity, a teenage boy named Clark Kent in the "real world" (where Superman is a just a comic book character) somehow develops superpowers like those of his namesake. After a brief career as a mysterious, non-costumed "Superboy", Clark dons the fictional character's colors and continues to work in secret as "Superman". Superman & Batman: Generations I-III, three limited series which present a unified cohesive history of many elements seen throughout the characters' history, with the characters interacting in real time from the early 20th century onward. In Batman: Holy Terror (1991), the body of an alien known simply as "the Green Man" with a similar origin to Superman is shown, and his origin is described during this story. When he sees the body of the Green Man, Batman is struck by sorrow, feeling as though the world has lost its greatest hope. During the confrontation with Doctor Erdel, the scientists responsible for analysing various superhumans for the Star Chamber, Erdel is killed when a bullet ricochets off the Green Man's chest to strike Erdel. The Booster Gold story arc "52 Pick-Up" briefly depicts a Superman in Booster Gold #3, when showing a timeline where Superman was found by Lionel Luthor and raised as Lionel Jr. alongside Lex Luthor. Lex finds out his brother's secret and ends up killing him a year later. The Hypertension storyline in Superboy #60-64 (1999) shows an alternative version of Kon-El named Black Zero. Black Zero is a genetically altered human clone of Superman (just as Kon-El was from 1993 to 2003) that has successfully grown to adulthood after Superman dies at the hands of Doomsday. For a time, he acts as the new Superman, even calling himself Superman 2. He exhibits both Superman's abilities as well as Superboy's tactile telekinesis. Without Superman alive to look up to, he instead views head of Cadmus Paul Westfield as his father figure. Eventually he turns to evil after a battle between himself and several of Superman's enemies results in the deaths of Matrix, Brainiac and over 300 innocent people which causes widespread persecution of clones. He first conquers his Earth, then enlists the help of the New God Metron to travel to alternative realities and conquer them as well to protect the clone community. He is defeated by the