Mystery surrounded Hwi's early life. It was known that she was heavily genetically modified or sequenced by the Ixians using technology they acquired from the Bene Tleilax. She was bred to heavily impact upon the God-Emperor's emotions and disrupt his Golden Path, which for 3500 years had a negative impact on many rival groups and cultures in the Empire.
Hwi's life prior to her arrival on Arrakis was spent in a no-chamber, where she was educated and conditioned by Ixian experts. It was there that her empathic and morally driven personality was developed. She was thus a stark contrast to her ambassadorial predecessor and uncle, Malky.
Relationship with Leto II
Shortly after Hwi's arrival on Arrakis, she met with the God-Emperor. As the Ixians had planned, he was immediately attracted to her, finding both her physical beauty and charming personality almost intoxicating. Hwi was specifically bred to appeal to the remnants of Leto's humanity. By tempting Leto in this way, the Ixians (and those allied with them) hoped that Leto would be tempted off his Golden Path, or, at the very least, second-guess it. They were correct - using Hwi in this way worked perfectly.
Leto suspected Hwi had been planted by the Ixians. But he knew she consciously meant him no harm and also found her irresistible, a combination that prevented him from dismissing or killing her. In contrast to this realization, Leto proposed to Noree, assuring her he was incapable of physical intimacy and promising her tacit approval of a lover if they were married. After thinking about his offer, Hwi accepted.
After months of planning and an increase in the amount of espionage and rebellious activity by his enemies against the God-Emperor, Leto hurried along his marriage plans.
As the pair passed over a bridge far above the raging Idaho River on their way to the wedding ceremony, Idaho, Siona, the unsuspecting Nayla, and other rebels, orchestrated an attack which caused the bridge to collapse. Realising her fate, Hwi Noree said to Leto, "I'll go on ahead, Love" before falling to her death. She was followed quickly by Leto, who dissolved into thousands of sandtrout upon hitting the water.
Noree played an increasing role in the events that foreshadowed Leto's death. The most obvious example of this came from her attraction to both Leto and the last Idaho ghola. This created a rivalry that widened the wedge between Leto and Duncan, and spurred Duncan to plot his assassination attempt on Leto.
However, it remains unclear whether Hwi Noree was more beneficial to Leto's opponents or to Leto himself. Her arrival helped to hasten Leto's death, the primary goal of the Ixians. But her impact on Leto highlighted his humanity, emboldened him to take the final step (death) to guarantee his Golden Path, and enabled humanity to move forward without his direction. And this, combined with his death, ultimately delivered the Known Universe down a critical part of his Golden Path.
Behind the Scenes
The character of Hwi Noree was one of the first Ixian characters to appear in the Frank Herbert canon. Prior to this, the Ixians were mentioned as a group, but did not appear in the dramatis personae of any Dune novel written before God Emperor of Dune.
She likes yogurt, When Leto II asks her if she is friends with Moneo, she says they are "friends of the stomach" in the fact that they both like yogurt.