Fan Casting Supergirl/Kara Zor-El in Superman 2: House Of El

Explains to Kal El that in the last days of Krypton, Braniac offered the same deal and also was responsible for the destruction of Krypton by secretly overly taking samples of Krypton's core and destroyed Krypton to cover up his crime? Maybe had materials that were unique as Braniac tries to calmly convey when Superman confronts him? Flashbacks to Krypton at the start when Braniac finally attacks