IOW, any denomination that you deem insufficiently orthodox. Got it.
That isn’t how a cult is defined.
That is exactly how a “Christian” cult is defined, they alter the identity of Jesus Christ.
In the case of SDA, they were founded by a false prophetess named Ellen G. White. She is the origin of many of their teachings including the belief that Jesus is the Archangel Michael. She claimed to have received a divine translation of the Bible called “The Clear Word”. Her teachings are given the same weight as Scripture in the SDA church. SDAs teach that all churches who worship on Sunday have the Mark of the Beast.