Garak

Elim Garak was a Cardassian male living in the 24th century, secretly the son of Enabren Tain. As a member of the Obsidian Order, Garak was one of Cardassia's top intelligence operatives, interrogators and assassins. By 2369, he had been exiled to Terok Nor. After the station was transferred to Bajoran ownership and converted to Deep Space 9, he continued to live there as a tailor. One of his greatest personal enemies was Gul Dukat, though Garak eventually fell in love with Dukat's daughter, Tora Ziyal. While living on DS9, Garak became a close friend of Julian Bashir, and had a unique relationship with Odo.

During the Dominion War, Garak was instrumental in the allied war effort as an intelligence analyst. Along with Kira Nerys, he helped lead the Cardassian resistance during the final days of the war, and remained on Cardassia Prime after the Battle of Cardassia. (, et. al)

Fanon data
During his years as an intelligence operative, and even after his exile, Garak had several encounters with Timothy Sinclair. By the time of Sinclair's return to Starfleet, they had a unique respect for each other, and a friendship of a sort. (, "Restoration", "Exile")