What is the ruling on a brother shunning his brother who wrongfully consumes people's wealth and slanders him, and what is the duty of the wronged brother towards his brother?

You must be patient with your brother's ill-treatment, seeking Allah's pleasure, and remember His saying, the Most High: (Repel [evil] with that which is better; then behold, he between whom and you was enmity [will become] as though he were a devoted friend. But none is granted it except those who are patient, and none is granted it except one having a great portion [of good]). As it is stated in the noble Hadith, whoever treats his relatives well while they treat him poorly, it is as if he is feeding them hot ashes, and he will have a supporter from Allah. You are not obligated to pay your brother's debts, for their sin is upon him alone, as Allah the Most High says: (And no bearer of burdens will bear the burden of another).