Kohzou Fuyutsuki
Kohzou Fuyutsuki used to teach meta-biology at Kyoto University before becoming Deputy Commander of NERV under Gendo Ikari. He's not a soldier by training—more of an academic who somehow ended up in a military role. The director's cut hints that he has medical training at some point in his past, though he never got or kept a license to practice. Nothing in the series suggests he had a romantic partner or kids; the flashback episode "The Birth of NERV" makes it pretty clear he was the withdrawn academic type, probably a lifelong loner who colleagues thought should get out more.
His path to NERV started when he took on Yui Ikari as a research assistant. Their relationship stayed professional and supportive—nothing romantic. Shortly after, his superiors told him to mentor a young man named Gendo Rokoboungi in the same way. Looking back, it's almost certain SEELE was already tracking him and grooming him for recruitment. If Yui really did have SEELE connections through her father, then his whole connection to Gendo was orchestrated from the start, a way of testing whether Fuyutsuki was smart enough, trustworthy enough, and willing enough for their plans.
Fuyutsuki never trusted Gendo—he even thought of him as "a real bastard" when they first met at a police station. But after running into him again during a research trip to post-Second Impact Antarctica, Fuyutsuki realized something darker was going on. He started piecing together that Gendo's SEELE connections were way more serious and dangerous than he'd thought.
When Fuyutsuki eventually figured out the truth about Second Impact and threatened to go public in 2003, Gendo brought him down into the GeoFront and showed him an incomplete Eva prototype. Then he basically asked Fuyutsuki to help him "create a new future for humankind." Fuyutsuki said yes. Whether that was genuine idealism or just self-preservation is never made clear—The End of Evangelion suggests SEELE threatened to make him "disappear," so it was probably both.
Despite not liking Gendo at first, Fuyutsuki becomes his closest thing to a confidant and moral anchor throughout the series. He's gruff but genuinely cares about the people under him, even when he has to balance that compassion against Gendo's ruthlessness and SEELE's horrifying agenda. Gendo leans on him constantly, and Fuyutsuki often takes charge without waiting for orders.
As for Yui—Fuyutsuki clearly cared about her deeply, though he always kept things professional. How he felt about the Dummy Plug experiment that killed her and trapped her soul in Eva Unit 01 is left unsaid. But the truth comes out right before Instrumentality, when he sees a vision of Lilith wearing Yui's face floating down to embrace him as he dematerializes into LCL. In that moment, it's clear how much she meant to him.
Content compiled by AnimeList.moe from publicly available sources.
