The original Jim Harper was the golden age Guardian, and the great-grandfather of Arsenal. When the current Jim Harper was cloned using genetic material from Roy Harper, he thought he was the grandson of his namesake.
Lietenant Marvel, real name Freddy Freeman,is one of Billy Batson's best school friendsand a former member of the Team. He joined the Team sometime after 2010, and left prior to 2015. His designation is B14
Merlyn was the secondary antagonist in the short; an assassin-for-hire contracted to kill Princess Perdita of Vlatava by her villainous uncle, Count Vertigo. In an unused scene cut for time, Merlyn taught Green Arrow how to shoot arrows.
Mary Bromfield was planned to appear in a story centred on the Marvel family in the companion comic. She was also planned to appear at Raquel Ervin's bridal shower in "Satisfaction" and the gathering of heroes in "Endgame", but there was not sufficient time to design the character.
Very early in development, Donna was considered as a leading candidate for the Team in season one, but was quickly removed from consideration for legal reasons. She was later made available, but too late for use in the first season.
She was planned to appear at Raquel Ervin's bridal shower in "Satisfaction" and the gathering of heroes in "Endgame", but there was not sufficient time to design the character.
An early proposal for the Young Justice: Legacy storyline had Zeus as a key villain, with the Team attempting to prevent an ancient and powerful weapon, the Spear of Reckoning (which might have been Zeus's thunderbolt), from falling into enemy hands. While the basic concept was approved, the use of Zeus and a Grecian weapon was rejected as Zeus is a good guy in Earth-16.
Zeus was one of the principal gods of Greek mythology, the king of the Olympians. In DC Comics, Zeus and the other gods are worshiped by the Amazons and the Atlanteans. He was also the father of Cassandra Sandsmark.
↑Though Sergeant Marvel's identity has yet to be explicitly confirmed, every other Team member's secret identity is known and Greg Weisman has indicated Mary Bromfield was a member of the Team. Thus, Mary must be Sergeant Marvel.