When she first appeared in Season 5 she was the bad guy who was taking other pony's cutie marks and would later be confronted by the Mane 6 and was defeated until she appeared again the season 5 finale attempting to alter timeline but would end up nearly destroying Equestria and forcing Twilight Sparkle to try and stop her until she finally got through to Starlight to convince her what she was doing was wrong and would later help her on the path to redemption through seasons 6,7,8.