Complex sentence: Meanwhile at a secret location, Lillian tells Lena that because they're Luthors, the public will always look at them as criminals, and convinces her to join Cadmus, but at the same time Metallo is starting to notice that his veins are turning green.
Split into simpler sentences: Meanwhile at a secret location, Lillian tells Lena that because they're Luthors, the public will always look at them as criminals, and convinces her to join Cadmus. At the same time, Metallo is starting to notice that his veins are turning green.