Zi Xia may be one of the characters that Kingdom invented for dramatic purposes – if she exists historically I’ve found no trace of her – but she’s fulfilling her role in the story quite admirably. And it’s certainly becoming clear just why Zheng finds the notion of an alliance with his mother such a disquieting thought. For all the physical abuse he suffered in Zhao (we’ve been spared the worst of it), the emotional abuse he took from her has clearly left a much bigger scar than the one on his arm.
It’s an interesting move, taking such a long detour into Zheng’s past at this point in the story – one that only a series with as much time to play with as Kingdom has the luxury to make. Zheng has actually been a largely forgotten character after the war of succession arc with his half-brother played out, but of course historically he’s the most important person in the story. We’ve always known he was a hard and determined youth, but I think it’s good that we’re seeing the extent to which he was pushed to it by the sheer ruthless angst of his childhood. Given what he’s going to have to do to achieve his goals, an understanding of just how hard a man he is makes sense from a dramatic standpoint.
Knowing that it was Lu Buwei who planned Zheng’s rescue (and that of his mother) is certainly interesting, given the rumors about Zheng’s parentage. It makes the three-way power struggle in Qin an even more fascinating one, though Kingdom still might take a pass on that aspect of the story. The practicals of the story are still focused on the rescue mission from Zhao, a suspenseful and nerve-wracking journey through a succession of gates where Zi Xia shows just why Lu Buwei chose her to lead this rescue (I especially liked her use of the Osaka-ben “Maido” at the second gate). Zheng’s struggles with his ghosts are perhaps a bit too heavy-handed, and his recovery due to her words to him in the mountain stream a bit too quick, but the basic emotions at play are portrayed very effectively. Zi Xia is literally the first person in Zheng’s life to show him any compassion at all, as far as we’re aware of. It’s no wonder he’s broken.
Sadly, it seems very likely the reward for her kindness is going to be the loss of her life. And even more sadly, it could be Zheng’s last breakdown that’s the cause – the delay that resulted from his leaping off the carriage allowing the mounted patrol from Zhao to catch up to the fleeing party. If that’s true I’d suppose he likely blames himself for her death, which would be yet another burden Zheng is carrying with him for all these years. In a sense I think this extended arc is the anime’s way of preparing the audience for what’s to come with Zheng, so that the character’s actions don’t seem completely out-of-character later. Seeing him as a boy incapable of feeling and unable to cry out even when pierced with an arrow changes the way we see him, even if Zi Xia managed to drag him back from the abyss with her kindness.