Rigel Crosser is a Templar Exiles agent, who was sent to interrogate Velia Scavo for information on Leah Acadal and the Assassins Order. While he is loyal to his Templar Exiles masters, he is ruthless and utterly without morals when it comes to his victims: he'd repeatedly tracked down and sexually abused Velia Scavo for almost a week, all the while interrogating her for information on Assassin Leah Acadal, before he was caught by Leah, and, a couple days later, killed in a fight with Leah and Vergil, when the former tracked down Rigel and Velia, and the latter followed Leah and intervened when Rigel almost defeated and subdued Leah.
After his actions against Velia, which were as serious as Blackmail, Assault, and Rape, were discovered, he was killed by Vergil Hamilton, who'd knocked over a pillar, crushing Rigel to death.