He's a cowboy on a flying horse.
And kinda lame. You need a few villains you can take shots at if you want to do comedy stories.
And you have Bounty who was kind of cool and criminally underused as more of a Baron Karza meets Clint Eastwood type.
I'd love to see Bounty, Lobo, and Terra-Man team-up.
Actually, I think I can think of one way to make Terra-Man more insufferable while making him a stronger villain:
Make him kind of a steampunk hipster. Instead of the one dimensional cowboy, have him be a gawky nerd who obsesses over mustache grooming and wears derbies and is slumming by cosplaying cowboy. And then once you make him completely annoying, you win a bit of audience sympathy back by giving him bad luck, bad assignments, and get dumped on constantly.