You either up the realism on the character model or scale it back on the environment, physics, sound, story, gameplay, etc..

The Team Fortress 2 art style would be perfectly appropriate to keep him looking smarmy and impossibly perfect.

A grittier character model like what you see in most modern war games would work too. You can still give a guy blonde hair, huge muscles, and dark glasses without making him cartoony. You'd just make him look like Ivan Drago or something.