I personally rank it as “interesting” more so than “puzzling.” Remember, we’re talking about an eleven-year-old kid here. I think the most telling line follows from “Keep running—I’ll distract whoever’s chasing you.”
The helot shook his head, eyes wide and fear-crazed. “No, child…just run….”
“Go!” Up to that afternoon, your sense of invulnerability had survived unshaken.
Ironically, Ulbern is completely correct. The only way to save you both is to run. There’s nothing else that a mauled helot and actual child can do against two Plektoi and a Theurge. When the Thaumatarchy sics Plektoi on your scent at the end of the game, you have to flee to the Xaos-Lands to get away (as Ulbern does). But a kid doesn’t know that — and neither does a new player.
You can try to save him with “a child’s confidence” and a “sense of invulnerability”: but both of those need to be broken for a rebellion to survive.
The real moment of decision is when you’re stared down by a man who holds your life in the palm of his hand. The only way to save Ulbern’s life is to have the courage to lie to that man’s face for the sake of a stranger. That’s an understated decision, because obviously we’re playing a rebel game, we’re going to lie to the authorities. But for the kid, that’s monumental.
Whenever you try to help Ulbern, there’s only one trail with his blood, and he’s moving slower (and into danger) because he’s doesn’t know this wilderness as well as you do, and then you’re caught along the same path that he ran. But when you run away, you’re going in the opposite direction of him with his blood and scent, and the Plektoi start chasing you. This buys Ulbern a lot more time to get away, and is what ultimately saves his life.
Saving Ulbern requires having the courage to act despite — maybe because — of one’s instinctive fear, and that’s rewarded: both the courage and the fear.
An easy way if you’re just going for the achievement is to have Ciels, be a Theurge, don’t be an asshole, save Pel from the crabs, heal the villagers, heal Veorn’s hand (this is optional, you don’t need to do it), stay, drive the reivers off, don’t stand up for Gredal, and you’ve got it.
In general, don’t stir up trouble, don’t talk to Gredal, help the village, play to the build’s strengths.