The first time he tried to move through space and time as the Observers did and couldn't was the first time feeling surged through him. He cowered, paralyzed. For the first time in his life, his mind was overpowered.
He felt trapped, and he didn't even know that he knew what feeling trapped felt like, but it was just like it had been like in his mind when the stasis rune trapped him and when the universe was hidden from him, only now his whole body was doing what his mind had done then.
Later he identified it as terror.