Vanto grew up on Lysatra found in Wild Space, where both his parents owned a shipping company that usually dealt in the Unknown Regions. Because of this, Vanto spent a lot of time picking up several languages, one of which was Sy Bisti. In later years, he became a cadet at Myomar Academy and was on track to becoming a supply officer.
During an expedition to the surface on an unknown world, Vanto and Captain Voss Parck were summoned by Colonel Mosh Barris, as he had found a hut which did not appear to match anything of known design. Vanto was summoned due to his knowledge and expertise on Sy Bisti, a language found written on supplies by the hut, which the Empire's droids could not translate.
Later on the same day, the Imperial settlement that had been set up was seemingly attacked by an unknown force, though Vanto was able to determine the attacker was a humanoid and had possibly been on the planet since the Clone Wars. Due to the attack, a decision was made to take the hut and everything in it aboard the Strikefast, where upon inspection, it was discovered the attacker was a lone Chiss. Vanto had learned stories of the Chiss, where he had heard that they too used the Sy Bisti language. The Chiss preferred to use this language to speak, which Vanto helped translate, however the Chiss was demanded he speak in Basic as it was observed that he understood the language. The Chiss then introduced himself with the name of Mitth'raw'nuruodo, or simply Thrawn.
On the Strikefast, Vanto was commanded by Parck to teach Thrawn more on how to speak Basic, as it seemed that Thrawn had difficulty with some aspects of the language. Parck believed Thrawn may be of interest to the Emperor due to Thrawn's tactical ingenious, and wanted him tutored for a potential meeting with the Emperor. During the tutoring lessons, Thrawn began to learn a lot about Vanto and became interested in his life and the Empire.
The Emperor was indeed interested in meeting the Chiss, Thrawn and Vanto, along with Parck, Barris, and several troopers who participated in the expedition, were called to Coruscant to meet him. During this meeting, the Emperor, realizing the Chiss race could one day become a prominent ally, enrolled Thrawn and Vanto into the Royal Imperial Academy to be inducted into the Imperial Navy, where Vanto was to be Thrawn's translator and aide where required. This decision confused and dismayed Vanto, yet unbeknownst to him, Thrawn took an interest in mentoring Vanto.
Graduating the Academy
Throughout the three months leading up to the graduation, Vanto and Thrawn became fast acquaintances with each other. Upon graduating, Ensign Vanto discovered that his duty, much to his dismay, would be to be the aide of the now Weapons Officer Lieutenant Thrawn on board the Blood Crow.
Vanto correctly deduced that his career would be negatively impacted due to being the alien's aide. After a visit to Coruscant, Vanto was approached by Culper, a member of Moff Ghadi's staff. She offer him a job, a job which would be vastly more luxurious than being an officer's aide, and would carry a higher position. Moff Ghadi had an objection to the quickening rise of Thrawn through the ranks, especially as a non-human. Ghadi's intent was to bring down Thrawn, and hoped taking away Vanto would help with this effort. When Vanto learned of this, and also experiencing Culper's prejudice toward those from Wild Space, he turned down the offer. Culper then promised him that Moff Ghadi would make certain that Vanto's career would be of no importance, and told him to get comfortable with being an Ensign, as he would hold that title for a long time, further implying Moff Ghadi's intent to curtail his career.
Vanto continued to serve with Thrawn after this encounter, and did so for a long time, including after the transfer from the Blood Crow to the Thunder Wasp, and after Thrawn took control of the aforementioned ship, and Thrawn's various promotions. During this time, Vanto's career appeared to be taking a negative turn as he held the rank of ensign longer than most, and for no overtly visible reason. Vanto had done little wrong, and had been involved in many successful operations engineered by Thrawn. Vanto of course, knew why no promotion had been given to him, yet Thrawn could not understand the lack of promotion, and tried to help his subordinate, friend, and student.
Thrawn met with Arihnda Pryce, and the two of them discussed problems that Arihnda was facing. She asked Thrawn to help her protect herself from prosecution being threatened by Moff Ghadi, the same person responsible for the stump Vanto's career. Thrawn agreed, and in return she promised to make sure Vanto would be promoted, and offered to aid Thrawn in the political arena, by using her networks in high places. To accomplish this, Pryce met with Grand Moff Wilhuff Tarkin and provided him with some incriminating evidence in the form of recordings of Moff Ghadi and several other senior officials. In return, she asked for governorship of Lothal, her homeworld, with Tarkin agreeing to those terms. Vanto and Thrawn would soon be summoned to Coruscant in a promotion ceremony, surprising Vanto for his inclusion in this occasion. Thrawn received a promotion to the rank of Commodore. Then, to Vanto's surprise, he was commended for his stellar career, and was subsequently promoted from the rank of Ensign to Lieutenant Commander, a surprising rise through the ranks, a very rare probability. Receiving new orders, Lieutenant Commander Vanto and Commodore Thrawn were assigned to the Star Destroyer Chimaera.
Since the incident on the Dromedar, during Thrawn and Vanto's missions, one name in particular continuously popped up in their investigations: Nightswan. Nightswan was continuously trying to disrupt the Empire's plans including instances where he would try and stop shipments of Doonium and Wookiee slaves from being sent to an unknown part of the galaxy for the construction of the Death Star, unbeknown to him however.
During the Battle of Batonn, after Admiral Durril and his 103rd Task Force failed in their attack, Thrawn and Vanto, now a Commander, launched a mission into smuggling vessels in the area of the battle, Vanto finally met Nightswan, who was pretending to be a weapons dealer fleeing from Scrim Island, and who ultimately revealed himself to be Nevil Cygni, somebody Vanto had previously met on the Dromedar. Nightswan originally thought that Vanto had met him alone, and that Thrawn had been conducting the attack on Scrim Island. Fortunately Thrawn had secretly arrived with Vanto, and faked a radiation leak onto the ship they arrived which gave Vanto the means to escape after being held at gunpoint.
Once Nightswan's personal ship had been destroyed with him on it during the battle, the fighting subsided, and the battle was over. Thrawn, seeing similarities in leadership, tactics, and strategy between Vanto and Nightswan, sent Vanto to meet with the Chiss Ascendancy, and specifically Admiral Ar'alani, who Thrawn believed Vanto could be a great ally to them in the years to come.