Yonkai

Stratus Colonel Yonkai is a cruel, corrupt officer in charge of the Cinderlands. He planned on finding Mushin's Legacy and using its power to take over the Empire himself. Through whatever means including murder, extortion and blackmail, he gathered information regarding the relic's location.

History
Yonkai requested to be assigned to the Cinderlands area in order to search for the coveted Mushin's Legacy. While making visits through his new domain, he arrived in Sandstone Refuge where he laid eyes on Lusung's older sister, Yujung. He immediately demanded her for himself, but Lusung's family refused to give her over on account that she was engaged to Hangwon. Yujung and her fiancee fled into the desert, but Yonkai's troops were quick to bring them back in.

Yonkai had Hangwon executed and sent his father to work in the Yonkai Excavation until he could no longer lift a pickaxe. Yonkai demanded that Yujung marry him, but when she refused once again, she was sent into the mines to work until the end of her days. Lusung attempted to go and free his sister but was quickly overwhelmed by Yonkai's troops. Angered at the blatant disobedience of Lusung's family, he had Lusung's parents executed and their bodies left in front of the village, prohibiting anyone from moving the corpses.

Yonkai's cruel treatment spread to the rest of the village, which he taxed heavily on top of forcing villagers to work in his mines under threat of death. Discovering news of Naryu Sarasva's existence, he had his officers and his mercenaries tearing apart the Scorching Sands searching for it.

He watched the treasure hunter Soha pick off an entire group of Yes Men with ease near Raider's Arc and hired her to aid in his search for the Naryu Sarasva.

First Arc
At some point, he began providing the Tyrian Cult with slave labor, in exchange for their Wraithbloom flowers which are force fed to his slave workers. He sent one of his officers, Yonkai Brigade Officer Sunna, to broker another deal with the Tyrian Cult within the Tyrian Storehouse but Sunna was quickly dispatched by the hero and Stratus Special Operative Choi Jina.

When he hears that someone has moved the bodies of Lusung's parents, he immediately suspects Miryung, a close friend of Lusung's family, and has her dragged off into the mines as punishment. He then hears word that Miryung was freed from the mines by the hero and that many of his soldiers were killed in the process. He begins searching for the hero in hopes of extorting them to find Mushin's Legacy for him.

When the hero appears before him to ask for forgiveness on behalf of Sandstone Refuge, he demands that the hero find Mushin's Legacy. He threatens that should the hero fail, he will kill everyone in Sandstone Refuge.

He makes a visit to the Yonkai Command Post near the Great Kilns, where the hero requests to see a record on Clear Sky's population to find information on the Mu Family. He gets angry that the hero hasn't found the Legacy yet and once again threatens to kill everyone in Sandstone Refuge and Clear Sky Village should they fail to find it.

The hero returns from saving the villagers of Clear Sky from the Grimhorn Tribe, relaying a message from Jang Jongwon that Clear Sky no longer wishes to move Yonkai's supplies due to safety reasons. Furious, Yonkai demands that one out of every ten men from Clear Sky will be tortured for their insubordination.

The hero discovers the location of the Silver Crest, one half of the key to access the Legacy and goes to gather it. During that time, Yonkai works half of Sandstone Refuge's men to death in the mine and has their bodies burned in the middle of town to send a message to the hero.

Yonkai moves to Raptor's Rise where he is notified by Advisor Jong Richu that the hero failed to find the Legacy at the Shadowmist Mausoleum. When the hero arrives to find out if Gil was able to speak with Yonkai on his next move, Yonkai explains that Gil kept talking about a girl named Yunwa and was sent on his way before he was captured by the Yes Men and brought to the Playpen. He angrily orders the hero to do their job while wondering if Yunwa is somehow tied to the Legacy.

He has his soldiers keep a close eye on Yunwa, ordering her capture should she leave the safety of Yehara's Mirage. As soon as Yunwa slips out of the Mirage with the Silver Crest, Yonkai's agents capture her and bring her to the Blindeye Bazaar. Yonkai learns that she has the Silver Crest and that all she requires next is the Golden Crest. Despite his best efforts, he is unable to make her reveal any more information and has her locked away in the Smuggler's Den. Yonkai awaits the hero's arrival at Po's Pub to order them to get Yunwa to talk. Immediately afterwards, Yonkai's honorguard rushes in to inform him that Juwol and the Yes Men are causing a disturbance in the Bazaar. When the Yes Men clear, Yonkai is furious to learn that the Silver Crest was taken in the chaos, telling the hero to go away.

Yonkai arrives with his brigade at the Wings of Mushin right behind Yehara, Juwol, and Soha, where the hero and Yunwa prepare both Crests to activate the way to Mushin's Legacy. Accusing them of attempting to steal his Legacy, he orders his troops to kill them. While the hero and Yunwa are away at Mushin's Tomb to gather the Legacy, Yonkai turns to see a Dark Dragon Pulse open behind him with Lusung stumbling out. Recognizing him, Yonkai taunts Lusung. With Jinsoyun's sudden arrival, Yonkai orders his troops to focus their attention on attacking her. He is horrified to see his entire brigade massacred before him before Jinsoyun kills him with Dark Chi.

Trivia

 * Yonkai notably has an odd habit of scratching his bottom before sniffing his hand.
 * All of Yonkai's Honorguard which are at his side at all times are pretty women: Bolyn, Dayu, Hyoson, and Coral.