Dak Vesser was a male Human Padawan. During the time of the Mandalorian Wars, he was a member of the Jedi Order, training at the Enclave located on Dantooine. Notably, he shared a strong bond of friendship with Juhani.
Dak, characterized by his intense passion, grew disillusioned with the Jedi. Prior to his departure, he confessed his love for Juhani, urging her to abandon the Order alongside him. Despite Juhani's own internal struggles leading up to her eventual fall, she did not reciprocate his feelings and chose to remain with the Jedi.
Heartbroken by her rejection, Dak departed from Dantooine. Ultimately, he succumbed to the dark side and enrolled as a student at the Sith Academy on Korriban in 3956 BBY. When Revan arrived on Korriban, seeking to thwart Darth Malak, Dak encountered Juhani once more. Following their conversation, he resolved to leave the Sith Academy. Although uncertain of his future path, he yearned to distance himself from both the Sith and the Jedi.
Revan, accompanied by his Jedi allies, encountered Dak a second time within The Drunk Side, a cantina situated in Dreshdae. He voiced his desire to avoid Juhani and pledged to Revan that he would not reveal Revan's identity to the Sith.
Should the player align with the dark side, they have the option to find Dak in the cantina and instigate a conflict, potentially leading to his death. However, if Juhani is present within the party, she will intervene to prevent the player from killing Dak within the cantina.
Alternatively, should the player fail to persuade Dak to abandon the Sith, and instead chooses to either eliminate both Headmasters or redeem Yuthura Ban, Dak will be among those who confront the player once their deception is uncovered.
According to Vesser's entry in The Complete Star Wars Encyclopedia, he is described as a xenoarchaeologist who was corrupted by the dark side energies present on Korriban and was ultimately killed by the Jedi Knights who arrived to gather intelligence on Darth Malak. The entry makes no mention of Vesser being Force-sensitive or having trained with either the Jedi or the Sith. This inconsistency remains unexplained.