Complex sentence: Pariah tracks down the Anti-Monitor at his fortress, and destroy a converter powered by stellar energy to destroy the last five Earths; the injured Anti-Monitor retreats and Supergirl dies.
Split into simpler sentences: Pariah tracks down the Anti-Monitor at his fortress, where he is using a converter powered by stellar energy to destroy the last five Earths. The heroes destroy the converter, the injured Anti-Monitor retreats and Supergirl dies.