I have an alternative theory to propose- Char blames Sayla for Lalah's death. In the flashback to Lalah's death in CCA, Char laments "If only my sister Artesia hadn't been there..." At the end of the fight with Amuro, Nanai signals for Char to retreat, and Char responds "Don't interfere in a battle between men!" It's the interference that really bothered Char, and he's itching for a shot to reenact RX-78 vs. Gelgoog, this time taking the battle to completion.Brave Fencer Kirby wrote:One of the interesting things about Char's overall character arc, from MSG to CCA, is the fact that he never blames anyone but Amuro for Lalah's death. He doesn't blame himself, either for putting her on the battlefield in the first place or for needing to be rescued (she intervenes in order to save him from Amuro, after all). He doesn't blame Lalah for choosing to sacrifice herself for his sake. He blames Amuro alone, despite the fact that Amuro was clearly just as horrified (if not moreso) by her death than Char was.
Really, I think the main thing about Char by CCA is that he's tired. He's spent his entire life trying to live up to his father's ideal, and trying to prod people into doing the same, despite the fact that he never really wanted to. He seems to do it more out of a sense of obligation than any actual belief in his father's ideals. After things have crumbled around him again and again (largely due to his own internal conflicts, but hey), he's really just tired of trying. But rather than just giving up, he decides to go out with a bang. That's why he gave Amuro the tools to stop him -- he didn't really want to win, he just wanted to go down fighting.
The ending of the Nu Gundam vs. Sazabi battle seems to parallel the RX-78 vs. Gelgoog battle. In the rematch, without the outside influences, Char still loses an arm and consequently the battle. All Char's scheming to set up the rematch, and the outcome wasn't any different than the first time around. It's the true defeat of his character, proof that Amuro was always his better.