Wei Zi was forced to repent by the queen.

In episode 13, due to the queen's instigation, the queen mother personally interrogated the murder of Gan Long by witchcraft. Wei Zi, Swallow, Golden Lock and others were frightened in prison, but in order to take care of each other, everyone pleaded guilty, and Wei Zi was finally executed at the Empress Dowager to protect the safety of Swallow, Golden Lock and others. ...