The Smiling Monster

"Well, let's head inside first," Krune told Hazak after that as the Cloud Whale slowly flew, arriving before the prison's entrance as he used his Sonic Radar. Thanks to his increased strength and his unceasing daily training, his Sonic Radar was leaps and bounds better than when he first arrived at Layer 2. 

Now, he was completely able to see through the entire prison, able to judge the material strength of the walls, scan through the people and demons within, and obtain a precise three-dimensional image of everything. 

On top of that, having used it enough times, he no longer had to think about what he perceived through Sonic Radar. Everything was instinct now. His brain didn't even need to process most of the information he perceived. Everything was already in him as muscle memory.