Some have the belief that the Force is the guiding principle in the galaxy, a power that creates and changes people's destinies based on their standing and actions taken. Nihlus goes against this grain. This Umbaran does not conform to any norms, whether they be social, procedural, technical, or cultural, instead having formed the belief that he alone controls and forges his own destiny.

This freedom allows Nihlus to make choices, moral or otherwise, that others may find hard and not be held back by the notion that the Force does not will him so and therefore he cannot or will fail in his endeavors. Unfortunately, this belief system also forces the Major to take more risks, sometimes putting himself or others in danger needlessly.

Nihlus' connection to the Force has been shattered due to a forever life-changing incident, forcing him to adapt and re-learn certain abilities without use of the Force. Also as a result of this trauma is a very minor amnesia, in regards to the identity and knowledge of his close friend and former master, Vodo Biask Taldrya. Ironically, Vexrii remembers every other person in his life in recent memory.

No longer an esteemed Sith Alchemist and Force User, Nihlus instead continues to operate as a soldier and pilot in service to Clan Taldryan as a member of the Taldryan Military and subordinate of Zxyl Venzos; using his immense level of mechanical aptitude and knowledge of the dark side to keep himself relevant without his prior abilities.

While he may no longer have a connection to the Force, Nihlus is still completely devoted to all mechanically related things to do with Sith technology, and retained his knowledge of Sith engineering after his accident. Nihlus Vexrii's drive to constantly modify and upgrade existing items, while pushing for the research and development of new-age Sith technologies and other Force, with the mentality now taking over part of his personality.

Vexrii has become much more of a secessionist, only extending his words to a select few inside his inner circle. His pursuit of becoming a master of Sith engineering within the Brotherhood has eroded any many of the relationships he once had in the Brotherhood, making him even quieter.

Nihlus' personality can only be described as icy, disciplined, and steel-like in his demeanor and interactions with others. He has built a hardened wall around his softer emotions. Vexrii is incredibly stubborn, believing his solution or answer to be the valid avenue of pursuit; with no room for errors or miscalculations on the part of others. He is ruthless in his tactics, devoid of mercy, and does not laugh.

The former Sith is normally quiet, with conversations short and to the point; preferring to leave no room for interpretation of his words. He also has no qualms about using torture to accomplish his goals. These traits have served Nihlus well at protecting his mental state, but have left him known widely as someone downright dangerous to be around.

With his connection to the Force gone, Nihlus has had to re-train many of his combat abilities, initially crippled in war from the loss of this connection. He has had to learn to improvise and adapt, developing new anti-Force user tactics to overtake these types of opponents. Never one to shy away from a challenge the Umbaran has worked extensively to retain as much of his skills with the signature lightsaber blade as possible, although he is still outmatched by those who use the Force.

Since losing his connection to the Force Nihlus Vexrii has increased the range at which he typically engages enemies, preferring to pick the off from a medium distance where he can formulate a strategy. This allows him to use blaster weaponry to take out some of his foes, still unsure and cautious of his untested skills in wielding a lightsaber again.

Nihlus Vexrii is utterly devoted to success in combat, no matter the mission, no matter the cost. He has spent his life building himself in the image of war, utilizing a dogmatic regimen that has lead him to a single-minded obsession with military success and requires intense physical and mental training. This training, however, has come at the cost of anything resembling empathy or concern for others - even his superiors and subordinates.