He was regarded as a cruel and capricious ruler, who acted at the whims of himself and his wife, Empress Fu Xunying, greatly damaging the Later Yan state.
Murong Xi was cruel and arbitrary as a ruler, willing to strike out at anyone who disobeyed him or whom he viewed as a potential threat.
In 403, he built Longteng Chateau (龍騰苑) within his imperial garden, described as occupying over two square kilometers and requiring forced labor from 20,000 men.
In summer 404, Murong Xi built Xiaoyao Palace (逍遙宮) at Longteng Chateau, with hundreds of rooms, and also constructed an artificial lake.
Murong Xi tied Wang to a palace gate and executed him by drawing and quartering, and then burned his body.
On this winter journey, it was described that more than 5,000 escorting soldiers died from attacks by tigers or wolves or exposure to the cold.
In other known events, she was described to be demanding to have jellied fish in the summer and fresh Rehmannia roots in the winter—neither of which could be obtainable—and Murong Xi executed officials in charge of supplying the palace for their failures.
In spring 405, Murong Xi, with Empress Fu with him, attacked Goguryeo's major city Liaodong (遼東, in modern Liaoyang, Liaoning), and had almost captured it.
However, he ordered his soldiers to flatten the wall so that he could enter with Empress Fu on an imperial wagon.
However, at Empress Fu's insistence that she wanted to observe a battle, he abandoned his heavy guard and took his faster cavalry to attack Goguryeo.
Murong Xi mourned her so much that, after having sex with her corpse,[1] he ordered that a magnificent tomb be built for her, and also forced his sister-in-law, Princess Zhang of Gaoyang (Murong Long's wife) to commit suicide so that she could be buried with Empress Fu.
Eventually, Murong Xi accompanied Empress Fu's funeral procession out of Longcheng.
Murong Xi returned to Longcheng and settled in outside, at Longteng Chateau, preparing an assault on the city.