An Imperial Security Bureau agent named Romwell Krass, Junior, a human male, served the Galactic Empire during the Galactic Civil War. He was assigned to a black-site prison located on the Hyborean Moon. Krass' family included his wife, Yileen Krass, his son, Qarwell Krass, and his father, Romwell Krass Senior. After the Battle of Endor, during a New Republic attack on the Hyborean Moon, Krass' family was killed. Managing to escape into hyperspace, Krass wandered the galaxy, grieving the loss of his family. While visiting Maz Kanata's castle on Takodana, Romwell, in a drunken state, assaulted a New Republic starfighter pilot. Kanata's droid, Emmie, intervened, halting the altercation and confining them to the dungeons. Taking pity on Romwell, Kanata advised him to find peace or face negative consequences. Romwell heeded Maz's advice and departed Takodana aboard his starship.
Living during the Age of the Empire, Romwell Krass Junior worked as an agent for the Imperial Security Bureau. He was the son of Romwell Krass Senior, the husband of Yileen Krass, and the father of Qarwell Krass. Before the Battle of Endor, Krass was stationed at a black-site prison situated on the Hyborean Moon. Krass considered his assignment at the Hyborean prison to be an easy one, and he used his connections within the Galactic Empire to secure positions there for his friends. He and his family enjoyed a comfortable life in a house located on the shore of one of the hot spring lakes.
In 5 ABY, Romwell's comfortable existence was shattered when the New Republic, the successor organization to the Rebel Alliance, dispatched a small fleet to attack the Hyborean Moon. The New Republic ships bombarded the Imperial housing structures, resulting in the deaths of Romwell's family. Krass narrowly escaped with his life as New Republic forces began to take over the prison. He escaped into hyperspace aboard a ship before the rebels could disable it.
Romwell attempted to contact the Imperial capital of Coruscant, only to discover that the Bureau there was under siege due to the Coruscant civil war. Romwell pledged to provide assistance, but overwhelmed by grief, he failed to report for duty and instead aimlessly traveled throughout the galaxy on his ship. Krass sought solace in alcohol while frequenting Maz Kanata's castle on the planet Takodana, attempting to cope with the loss of his family.
One day, Romwell observed a New Republic pilot and his girlfriend enjoying a song by Minlan Weil and the Tam-honil Three. Consumed by rage, Krass, who was intoxicated, attacked the pilot. However, due to his inebriated state, the pilot's girlfriend was able to outmaneuver him and strike him in the nose. The pilot then grabbed his ankle and threw him against a chair. As the New Republic pilot began to punch him, Romwell spat blood in the rebel's face, temporarily blinding him, before throwing him against a table.
Before Krass could conclude the fight, Maz Kanata's droid, ME-8D9, intervened, separating Krass and the Republic pilot. When the droid informed him that he had violated the Castle's law and that punishment was imminent, Krass defiantly stated that he would do it again. ME-8D9 then incapacitated Krass with an electric shock. Upon regaining consciousness, Krass found himself confined in Maz Kanata's dungeons. After vomiting, Krass crawled to the door and cried out for help. The New Republic pilot responded that they were both in trouble with Maz Kanata. The two then engaged in a verbal exchange, trading insults about Imperial and rebel atrocities committed during the Galactic Civil War.
Maz Kanata then entered the dungeons to speak with the two troublemakers. When the rebel pilot apologized for his actions and attributed the fight to Romwell, Romwell condemned the rebels as brutes. Kanata then silenced them both and instructed Krass to approach her. Through the Force, Maz sensed the pain in his eyes. Acknowledging that he had experienced loss and regret, she cautioned him that he had also inflicted pain and loss on others, adding that the scales are balanced.
When Romwell inquired about her meaning regarding the scales and her people, Maz responded that the Empire was currently dead. However, she foretold that the remnants of the Empire would give rise to new creatures. Taking pity on Krass, Maz granted him his freedom but warned him not to return to her castle. She also advised him to keep his pain to himself and seek inner peace, lest he bring harm upon himself. The New Republic pilot agreed to leave, but only on the condition that Krass left first. Romwell complied and quickly departed Maz Kanata's castle, heading to an unknown destination. After Krass's departure, Maz announced her intention to travel the galaxy for a while aboard the ship Stranger's Fortune.
Romwell Krass Junior was an Imperial Security Bureau agent who was stationed at an Imperial black-site prison on the Hyborean Moon. Krass deeply loved his wife, Yileen, and his son, Qarwell. Krass believed that his son possessed the potential to become an excellent ISB officer. As an ISB agent, Romwell harbored a strong hatred for the Rebellion and inflicted considerable suffering and pain upon the rebel prisoners at his prison. Krass was devastated when his family was killed during a New Republic attack on the Hyborean Moon. Overwhelmed by grief, Romwell abandoned his duties and turned to alcohol. Krass's inability to cope with his grief led him to attack a New Republic pilot on Takodana. Despite his aversion to aliens, Romwell respected Maz's advice to find peace and come to terms with the loss of his family.
Romwell Krass Junior made his first appearance in Chuck Wendig's 2016 novel Aftermath: Life Debt, which is the second installment in the Star Wars: The Aftermath Trilogy. The 2019 reference book Ultimate Star Wars, New Edition incorrectly identifies Krass as a First Order pilot.