On the episode's special feature, Bruce Timm said frankly that he was disappointed with the way the episode turned out: having set up an interesting human premise in Part I -- Zander's sheltered upbringing and his surprising friendship with Terry and Max -- Part II abandoned that theme and ended the episode with a conventional action climax.
Zander stands in for the supervillain Kobra, raised from birth to run the eponymous cult. His backstory also seems to be a homage to G.I. Joe villain Serpentor: both are genetically created to be monarchs of Kobra/Cobra.
Batman: Arkham Knight, there's a poster advertising Tanaga Dojo in Oracle's study inside the Watch Tower. Kairi is billed as the instructor.
Dr. Childes says that the dormant volcano stands on top of a rift extending "halfway to the Earth's core". By definition, only the relatively solid layers of the Earth can have rifts, and they don't extend nearly that deep.
When Zander tells to Max his origin story, one of the flashback shows Dr. Abel Cuvier, the creator of the splicers. It appears Kobra used his researches for fulfilling their plans and that the doctor was part of the organization.