In disbelief, Kriss and Pauline watched him destroy the landscape in rage.
After seeing his extraordinary strength and having witnessed him doing several seemingly impossible things, all while appearing mostly calm and collected, they had come to view him as a dangerous but level-headed guy.
So, seeing him rage like this, they couldn't help but wonder just what he had heard in the message he received a while ago that made him go out of control like this.
They also felt a bad feeling well up in their hearts because they vaguely felt whatever had happened had affected them too. The only reason they were just watching him while suppressing the unsettling feeling in their hearts was because they didn't know what exactly had happened.