The Core Era refers to the four seasons primarily associated with The Core Family and their history with each other. It acts as a jumpstart for the series, and explains how this dysfunctional family really works.
After her father is mysteriously resurrected into her son's unborn child, Antoinette Core and her sister must team up with the son and husband to destroy the man (now a young child), before he ruins all of their evil plans, like he did in his past life. He has lost all of his memory, however. Together, they construct an elaborate plan, which involves all of them building up the young boy's emotions, and then crushing them, and ditching him in a parallel world. They trick the boy into thinking his parents are Jamison and Antoinette, and that David saves him from their torture.
They then reveal to him that David was his father all along, and that Antoinette and Jamison were DAVID'S parents. Then finally, they send themselves all to Limbo, and attempt to lock Mozart in, leaving them with two bombshell drops: One, David was evil all along, and two, Mozart had a previous life. The boy rips David's powers away, and escapes.
Reconnecting to his past life, Mozart finds his widowed wife, who jogs his memory. Meanwhile, Antoinette and her sister are stocking up on weapons to end their parents before they interfere any further. The outcome of all of this chaos? Marina dies, Mozart nukes Antoinette's Mansion, and all of the villains escape to Jane's Mansion, only for Jamison to discover that Jane's servant was his father all along, and Jane had kidnapped and tortured the old man for years.
This sparks a civil war, and the villains split up, losing David in the process. Using the city mayor, whom they hypnotized, Antoinette and Jane lure Mozart and the men back to Jane's estate, attempting to jail them. Mozart escapes it. The men are captured. Later however, Mozart is taken from his very own home, and strapped down in Jane's Lab.
Taunting the girls, Mozart makes fun of how they lost their master. The girls want to prove to them their loyalty to their master, whom hypnotized them both to become evil, and also was the one who killed Mozart and his brother in their sleep, all those years ago, before he was resurrected. The men and women construct a Time Machine, and go to the past, bringing the master to the present, where it is revealed that all along, it was Mozart's past life's mother.