Since Prince Wei returned from Jinling, he has changed; he seems to have replaced the deposed Crown Prince, becoming a new force in the court. Though not entirely new, Prince Wei took over the remnants of the deposed Crown Prince's influence.
Even though the Crown Prince's power had been mostly eradicated, some remnants remained. These were once the Crown Prince's trusted aides whose positions weren't significant, hence they escaped disaster. They were loyal to the Crown Prince and, seeing him deposed by Prince Chu, were determined to avenge him.
Now, with Prince Wei seeking vengeance for the Crown Prince, they are naturally willing to follow him. Before Prince Wei returned, they were resentful towards him, believing it was his inability to handle matters that allowed Prince Chu to gather evidence against the Crown Prince.
Whatever Prince Wei told them, they not only ceased to resent him but were also very grateful.
