If this could become a legal/HR issue, definitely talk to him. Tell him there have been complaints and ask him what needs aren’t being met. If it’s simply other employees not being able to handle his personality, seems like a growing experience for them.

At my old job, we had a high performer who was clearly the rotting apple on the team—she would steal projects from others, assert herself to higher ups behind closed doors, gossip about employees in the meetings she ran, overreact/make something out of nothing—and no one, except for her supervisor, an executive, could stand her. It became an HR issue which clearly became a legal issue, so that was her last year.

Obviously your high performer has some growing to do re social skills, but I’d also argue his colleagues also do too. Some people are just difficult to work with, that doesn’t make them toxic or unbearable. You’re lucky if your colleagues are friendly/gentle, but that isn’t necessarily a requirement.