Complex sentence: As continued in "Justice League Unlimited", she and Superman have grown very close, almost like siblings, but she departs his company when she discovers love for Brainiac 5 of the Legion of Super-Heroes in the distant future.
Split into simpler sentences: As continued in in this show, she and Superman have grown very close, almost like siblings. She departs his company when she discovers love for Brainiac 5 of the Legion of Super-Heroes in the distant future.