Kluber is still in his prime. Multiple Cy Youngs. I think it's clearly him.
Lindor is the second biggest personality/face of Cleveland sports. Thomas arguably has 2nd best overall career in the city right now. But Kluber is the best athlete next to LeBron. It was a shame he threw garbage against the Yanks, but what are you gonna do? Lindor and Ramirez weren't good either and Thomas has never sniffed the playoffs (not blaming him but ugh).
EDIT: Love has a case as well because he's still prime and putting up 20-10 as an All-Star, but there is zero question that Kluber is a more valuable asset to the Indians than Love is to the Cavs.