Code of Civil Procedure Article 71

In cases where there are two or more advocates, each advocate may represent the party independently.Retention in violation of the provision of the preceding paragraph shall have no effect on the opposing party.
中文原文 民事訴訟法第71條
訴訟代理人有二人以上者,均得單獨代理當事人。
違反前項之規定而為委任者,對於他造不生效力。

English translation for reference only; the Chinese text prevails. Not legal advice.