The Brave and the Bold, a new form of James Gunn's DCU Chapter One slate, is a collection of comic book titles that have been stripped wholesale from previous ones. This implies a certain degree of faithfulness to what's been published previously, although we're not optimistic that Gunn's Man of Steel remake will be as damaging as Superman: Legacy.
The most authentic TV adaptation of the Last Son of Krypton there is arguably Superman: The Animated Series, the second entry in the famous DC Animated Universe of the 1990s and 2000s that kicked off with Batman: The Animated Series. After three seasons, S:TAS was later repackaged as a TV film, which just happens to share a title with Gunn's new film.
The two films are unlikely to have much in common in terms of plot, but the animated film, which is presumably intended for younger audiences, is likely to be the more hardcore of the pair, given that its plotline could've been imagined by Zack Snyder. The horrific opening to Legacy opens a new world that is subjugated by the forces of Apokolips, led by a brutal armored solder who is identified as the son of Darkseid.
Darkseid brainwashed Kal-El into believing his pod crashed on Apokolips rather than Kansas, and that he was raised by the evil overlord. Clark finally comes to his senses when he spots Lois Lane in a haunting Justice League moment.
As this was the final episode of the show, Legacy served as a rather depressing conclusion — although Superman would return and face Darkseid again in the follow-up Justice League series.
There is little chance that the next Superman: Legacy film will deliver the same kind of Kryptonian-powered punch as the previous one.