In one of the GI joe Sunbow episodes, Zartan is double crossed by the evil Dr. Mindbender, and is therefore forced to help GI joe in a desperate move to save his hypnotized sister Zarana from becoming the Cobra organization's next victim.
Zarana gets obviously rescued at the end of the episode, and Zartan is still the same bad guy that we know until the end of the entire series.
What do you believe Zartan would've done if something bad would've happened to Zarana?