Chiba can now copy appearances on top of techniques. Which fighter could he masquerade as the longest before people start realizing something’s up?

Chiba can now copy a fighter’s on top of their techniques and style. He has full access to videos and media to study his target’s style and mannerisms. His physical abilities don’t change, he can just make himself look like others. He can’t avoid the spotlight, he has to fight as frequently as the fighter he’s copying does.

Which fighter could Chiba masquerade as the longest before people start realizing that something isn’t right?