He is a faggot who couldn't swallow his pride and apologize to Reinhard, which resulted in the deaths of hundreds of thousands of soldiers in the fighting that followed. Fuck him.
Sure, he's not perfect, but that's why we love him. Yang and Reinhard have noble causes, Reuenthal is just an asshole put into a difficult situation. He's really no worse than Reinhard at that point, who was clearly seeking battle for battling's sake.
Or an anime character more cute than Yang?
It's fucking terrible; you should stay away from it.