Assalaamu alaykum. In Indonesia, there is an ethnic group called the Dayak. Some of them mix their animist beliefes with Islam, and some scholars also support it because it represents "traditional Islam" for them. These beliefs include some mystic and odd rituals together with some anti-Islamic belief. Is this permissible?

All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad is His slave and Messenger.

The belief of the person in animism (spirits) and that they may bring a benefit for him or repel harm from him is an evil matter that leads the person to disbelief in Allah. What you mentioned, that some Muslim scholars approve of this evil and consider it as a traditional Islam is very strange, as we do not know which Islam they mean.

The religion that Allah revealed to His Prophet and which Allah has approved for the people is based on Tawheed (Oneness) of Allah in His Lordship, Divinity, and His Names and Attributes. Its foundation is the belief that Allah alone is the One Who benefits and harms. Allah says (what means): {And if Allah should touch you with adversity, there is no remover of it except Him. And if He touches you with good - then He is over all things competent.} [Quran 6:17] Allah also says (what means): {And if Allah should touch you with adversity, there is no remover of it except Him; and if He intends for you good, then there is no repeller of His bounty. He causes it to reach whom He wills of His servants. And He is the Forgiving, the Merciful.} [Quran 10:107]

What is required is to give advice to all; the common people and the scholars, as it was confirmed that Jareer, may Allah be pleased with him, narrated that the Prophet said, “I pledged allegiance to the Prophet to establish the prayer, to pay the zakah, and to give sincere advice to every Muslim.” [Al-Bukhari and Muslim]

The scholars in particular must be reminded of their responsibility to clarify the truth and guide the nation to it, as Allah says (what means): {And [mention, O Muhammad] when Allah took a covenant from those who were given the Scripture, [saying], "You must make it clear to the people and not conceal it." But they threw it away behind their backs and exchanged it for a small price. And wretched is that which they purchased.} [Quran 3:187]

At-Taahir ibn ‘Ashoor said in At-Tahreer wat-Tanweer, “Even though this verse was revealed about the People of the Book, its ruling includes the Muslims who do the same thing like them, as the type of ruling and its reason can apply to them.”

Allah knows best.