What is the ruling on shunning a brother who wrongs others, knowing that he apologizes and then returns to wrongdoing? And are my deeds accepted after I swore not to speak to him except by my own will? And what is the way to reform him and impel him to stop wrongdoing?

Maintaining kinship ties is obligatory, and severing them is forbidden. The one who maintains ties is he who connects with those who cut him off and does good to those who harm him. A Muslim should seek reward from Allah when connecting with those who cut him off, and Allah will aid him. Removing disputes among Muslims is obligatory because they shave off religion. A Muslim must beware of harming believers, severing kinship ties, and insulting a Muslim. As for the oath not to speak unless it is by your will, the intention specifies and restricts the oath, so you may speak to him without breaking your oath.