Complex sentence: Korvac returns for her, and Hank Pym offers to return Carina to Korvac, but she refuses to go with him; she chose nonexistence over him (even though she is apparently immortal, as is her father).
Split into simpler sentences: Korvac returns for her and Hank Pym offers to return Carina to Korvac, but she refuses to go with him. She chose nonexistence over him (even though she is apparently immortal, as is her father).