Hien is a Midlander Hyur with messy black hair tied back in a topknot with red and orange ribbons and a beard trimmed to his jawline. He wears a yellow fur-trimmed robe with misty mountain designs and light armor. Being a Doman samurai, Hien carries a katana with an ornate design.
Hien harbors a deep sense of honor and duty to his country and initially feels great remorse for the fall of his kingdom, but believes if his people are content under Garlean rule, he would not force them into revolting just to put himself on the throne. He carries a friendly and competitive attitude among his peers, liking to make a contest out of tasks involving strength. He is a capable leader and puts the safety of his people above his own status.
Hien decides to destroy Doma Castle if it means ending the siege sooner with less bloodshed. He occasionally clashes with his trusted companion Gosetsu Everfall over the subject of tradition (the latter objects the destruction of Doma Castle because of its historical significance), but Hien believes one should not be weighed down by the past when forging a new future.
Hien is has been hiding at the Azim Steppe since the defeat of the Doman resistance. When approached about returning to lead the Domans, he agrees if his people wish to continue the fight, not wanting them to suffer the empire's wrath unwillingly. After being shown their desire to try once more to overthrow the imperial occupation, Hien agrees to return, though he first needs to gather an army, planning to create one from the many Xaela tribes that populate the Azim Steppe.
Hien allies with the Mol Tribe, and agrees to lead them to victory in the upcoming Naadam, the ceremonial battle that determines the leadership of the Steppe. Along with the Warrior of Light, Gosetsu and Lyse, he meets with the leaders of several of the other Au Ra tribes and completes the trial at Bardam's Mettle before winning the Naadam for the Mol. Once the tribes unite under his leadership during the fight against the empire, Hien returns to Doma to prepare for the upcoming battle.
He supports Alphinaud's plan to defeat the imperial occupation, but later modifies it to include the flooding of Doma Castle. Although destroying the castle would be a great loss to his country, doing so would drastically decrease the casualties among his people, which he sees as being far more important. The plan succeeds, and the Garlean forces are driven out. As the Scions of the Seventh Dawn prepare to return to Eorzea, Hien thanks them for helping liberate his country, and promises to return the favor by helping them in the upcoming battle to defeat the imperial forces at Ala Mhigo.
He is true to his word, as he leads the Xaela tribes to provide crucial air support to the Eorzean Alliance at the final siege of Ala Mhigo, and he helps fight off imperial soldiers outside the throne room.
- The former Doman king, Kaien, his wife, Mina, and the prince, Hien, allude to Cyan Garamonde and his wife and son Elayne and Owain from Final Fantasy VI. Kaien's name is based on the romaji of Cyan's Japanese name, Cayenne (カイエン?), Mina's name is the same as Elayne's Japanese name, Mina (ミナ?), while Hien's childhood name, Shun, is based on Owaine's Japanese name, which is also Shun (シュン?).
- The party finds Hien on a cliff similar to how Cyan is found in the World of Ruin in Final Fantasy VI.
- Hien's childhood name, Shun, was given to him by his mother and he gets embarrassed whenever he is addressed as such.
- Of the leaders of the free world who resist the Garlean Empire, Hien is the only one who is part of a monarchy, having succeeded his father as leader and liberating his homeland of Doma.
- Ishgard formed a republic following the abolishment of the theocracy with Aymeric de Borel becoming the elected Speaker of the House of Lords, thereby the leader of his nation.
- Nanamo Ul Namo is technically still the sultana of Ul'dah but she still plans to transfer her government into a republic.
- Gridania is ruled by a council of Seedseers, though Kan-E-Senna is the de facto leader of her nation.
- Limsa Lominsa is a thalassocracy, where sea captains prove themselves in a competition, with Merlwyb Bloefhiswyn serving as the leading admiral.
- Recently liberated Ala Mhigo has yet to establish its own government with an ideal leader but there is an intent to form a government modeled after Ishgard's House of Commons.