'It turns out that he is so powerful, but why did he hide his strength?'
When Grady caused a scene at the wedding, Darryl had beat him up mercilessly in the reprisal that followed in public. Lolita did not think much about it at that time; she thought that Darryl was just lucky. When she saw Darryl summon his Heavenly Halberd, she finally realized that the man was much tougher than she thought.
"Darryl!"
Grady reacted by covering his face and yelling at Darryl. "Finally, you revealed your tru