With all of the super-powered aliens running free on Supergirl’s world, it’s hard to really envision a human as being much of a threat. But that’s only because the only humans who have ever seemed threatening enough to the house of El are the Luthors.
Recently revealed to be behind Cadmus is Lillian Luthor, Lena and Lex’s mother. Her intent is to rid Earth of all alien life. In the show’s last episode, Lillian was able to get a hold of Supergirl’s blood and sent Cyborg Superman, formerly known as the real Hank Henshaw, to the Fortress of Solitude to find out about a virus called Medusa.
Lillian’s portrayer, actress Brenda Strong, discussed her character’s plans with Medusa.
“Lillian’s objective is to rid the Earth of what she sees as an invasive, infectious force, and that’s the alien population. In her mind, using Supergirl’s blood to unlock the key to get the deadly Medusa virus, that’s her way of manipulating science to fulfill her objective, to get rid of as many aliens as possible within a small region, including Supergirl. [Lillian] is more of a threat than people can possibly imagine.”
But Lillian’s daughter, Lena, has grown closer to Kara and Supergirl. This doesn’t please Mama Luthor at all and all the buildup will lead to an emotional aftermath between mother and daughter.
“Lillian and Lena have been operating in their relationship at a slow simmer this entire time and the gas just got turned up, so whatever is boiling underneath, it’s going to come to the surface in the next episode. You’re going to see an explosiveness between the two of them. She’s never been happy about any of her children being close to Supergirl or Superman since it will only end badly. She definitely will feel betrayed [by Lena working with Supergirl] and there’s going to be major emotional aftermath from that.”