Well, this is a skill like anything else. You have to train it, have to figure out how to use it. My fruit seems particularly hard to use.

[Or maybe he's just bad at it. So many others can do so many things with their rewritten bodies. Many also learn to wield the innate powers of the sixth sense, haki, said to be something everyone possesses. But he's never felt it either. He had the best instructors a Marine could ask for and not once could he manage to harness those powers of armament or observation, while his brother was causing crowds to fall at his feet under sheer willpower at the age of eight.]

Like this barrier, it's a double-edged sword. They can't hear anything we're saying right now, those spirit creatures, and that's the real benefit. But as you can see, we can't hear them, either.

[It's far from the only thing he can do, of course, but it's enough to show he can do something. He'll keep the rest to himself.]