What Ace saw was Peter had succeeded in locking Dallas with his shadow lock skill and then many people focused on dealing damage to the ghoul. For a note, it was just less than 30 minutes from when Peter went to face Dallas.
He had expected something like this to happen, but to happen this fast was something he had never thought about. He then saw Dallas's HP decreased at a rapid pace.
32%
30%
28%
25%
Then Ace saw the ghoul was freed from the skill and wanted to run. As it was such a good opportunity, Ace thought it was such a loss if Dallas didn't die. Ace decided to help them.
Ace then took a Joker card and threw it to Dallas who wanted to run. As it hit him, three fire snakes were holding the elite ghoul.
From afar, Ace could see the ghoul's surprised and panicked expression. Peter also seemed to be surprised. However, after seeing Ace on top of the town wall, he seemed to realize that it was Ace's doing.
