R'ug grew up on Glee Ansem as a son of the prestigious House of En, a minor noble family. His noble upbringing ensured he had access to most everything he could ever want, yet his family's low position always put him in the perfect place to watch his superiors in society have more. R'ug grew to bitterly despise most anyone else that had more than he did and always strove to possess the best of the best, an ambition that lead him off his homeworld and to exploration of the galaxy in various business ventures. This same self-destructive and blinding envy and ambition also led him to have a profound hatred of Force-users upon encountering some of them in the Outer Rim Territories, and he seeks to tear anyone with such powers down and climb atop their corpses, just as he would with anything else he desired for himself.

Despite his teachings in courtly ways, R'ug En took only the practicalities from his noble education and none of its idealism. He cares nothing for honor and has the moral compass of a nexu, willing to do anything to accomplish his goals or amuse himself through others' suffering. Any oath R'ug gives is a deceptive means to an end, and anyone going to him for protection is as likely to end up strapped to a laboratory table as thrown out an airlock. Nevertheless, R'ug En's selfishness demands he keep certain bargains and observe the rare streak of fealty, and he works as a diligent right hand to Tissflorin in the hopes of one day usurping her and taking over Capital Enterprises for himself. Of course, his callous habits have left a string of enemies in his wake who live for their revenge, and he's liable to keep making more.

R'ug En is fascinated by the study of pain and its expression in all forms. While this is focused mainly on the suffering of sentients, it also applies to animals and droids — no puppy will go unkicked if R'ug En is nearby to study the effects of such lashings. The Nautolan is sadistic and cruel and fascinated with torture and torment, enjoying toying with everyone he meets both mentally and physically, whether it's an application of the perfect word to cripple confidence and hopes or the precise insertion of a knife under a fingernail. When he is not dreaming of socioeconomic domination, he is dreaming of domination over others, to hold their lives in his hands. This, of course, leaves him little liked if marginally useful, and his subordinates have a terrible habit of deserting him if the fear of retribution doesn't keep them bent.

R'ug En is obsessed with himself and with respect paid to him. Megalomaniacal and narcissistic are only two terms one may apply to the man, and are perhaps the kindest available. R'ug En shows only the slightest respect or obedience to those he works for and expects nothing but pure loyalty and unquestioning fear from everyone else — man, woman, or child. He is incredibly harsh if he feels slighted, and will lash out to punish those who give him lip or simply don't step lightly enough when he's around. With a hair-trigger temper and a history of being allowed to get away with whatever he liked, the Nautolan is a terrible presence in any room, and reacts very poorly to any rebuke. His peevishness gets him in many difficult situations he cannot always conquer and makes for poor diplomacy, nevermind friendship.

Tutored by some of the best and most expensively paid masters Glee Ansem and other worlds had to offer, R'ug En is a masterful duelist and wickedly skilled in all forms of bladework. He mostly prefers swords for combat, considering the image of himself with a rapier proud and handsome. Smaller knives tend to be saved for torture sessions, but he is not entirely picky. Regardless of the bladed tool in hand, R'ug En prefers to draw out any engagement and subject his opponents to a death of a thousand cuts, slowly slicing them to pieces. However, the Nautolan is easily outmaneuvered if caught outnumbered away from the entourage he hides behind, and he is deathly afraid of...well, death. If it seems his life is in peril, he will immediately cower and attempt to bargain, as soon throwing any allies to the sharks or sacrificing missions as anything else.

R'ug En fights primarily to cause pain, and is not one to be quick or direct by any means despite his somewhat pragmatic nature; not where his obsession is concerned. He considers interacting with others, especially where weapons are involved, to be a delightful game for his amusement. R'ug En often instigates any engagement by goading and taunts meant to eviscerate and intimidate, proceeding from verbal torture to physical debilitation. He does not like to kill his opponents; rather he slowly unravels them and, if possible, captures them for more "fun" later. This practice is frivolous and dangerous, and leaves plenty of opportunity at any stage for him to be overwhelmed while he is busy entertaining himself in his hubris.