Yeegar is the most senior of the five Generals, known for leading from the front lines and taking on the hardest battles first. He's famously strict about manners and proper conduct—something Komui and others frequently mention—but he's genuinely kind underneath. He loves cooking and was apparently thrilled to whip up extra food for Allen Walker after watching him demolish the meal Yeegar had prepared.
His story ends tragically. Tyki Mikk targeted him specifically, brutally defeating and mutilating him in what amounts to an execution. The attack destroyed his Innocence and left him mentally broken; he spent his final days ranting about "the Heart" and the Earl's obsession with it before succumbing to his injuries. Notably, he refused to let his finders stay during the assault, forcing them to escape while he held the line.
In the manga, readers only learn about Yeegar after his death through Komui's explanation to Allen, Lavi, and Lenalee. The attack was catastrophic—he'd been safeguarding seven pieces of Innocence along with his own, meaning eight total were lost when the Earl destroyed them.
The anime expands on his background considerably. He carried a pair of chained pendulums as his anti-Akuma weapon, capable of splitting into multiple projectiles to hit several enemies at once. Before joining the Order, he was a teacher. When one of his students died and her friend turned her corpse into an Akuma that slaughtered the entire class, an Exorcist with a bow defeated it and told Yeegar about the Black Order—which inspired him to become an Exorcist himself.
Content compiled by AnimeList.moe from publicly available sources.