Klaus trying to take on Trunks would be a spectacle for all to see. Especially if Trunks was determined not to fight back. It would be a lot of dodging and blurring around at speeds the human eye was incapable of keeping up with. Trunks was stronger, faster— From what he knew of her brother, that would be absolutely unacceptable.

But Trunks was also half-alien. He was cheating, in a way. Cheating at being better, cheating at being stronger. He was more formidable than anything this world had to offer, because his father wasn't from this world. His DNA was only half-human, and while there were aspects of his human physiology that played a part in amplifying his strength, that wouldn't be possible without the parts of him that were bred on another planet.

"I wouldn't call the last living member of a dying race special."