Let me make this easy for you.
It boils down to the Person, Nature and Work of Christ Mormonism uses extra biblical sources to define Jesus as a created being who is a brother to satan as well as to us ontologically. It teaches from extra-biblical sources that there are a plethura of gods inhabiting the universe - each as a god over their own planet. It claims that Jesus is just another one of these 'gods'. Mormonism teaches that Christ's death was only sufficient to allow for a general resurrection of humanity. But to reach the highest heaven (once again relying on extra-biblical sources) man must do specified works, ordinances and actions in order to score enough points to become a god.
The Jesus of Christianity is the eternal uncreated creator, who created satan and his angels as well as created humans. We in no fashion are ontologically related to Him. The Jesus of Christianity is the Second Person of the Trinity - 3 Persons, 1 God - and is NOT polytheistic as taught in Isaiah. Jesus' death on the cross was completely sufficient for ALL my sin and his grace in giving me that full eternal life is not dependent upon any works that I could do - but is a complete gift to me.
Jesus cannot be both things at once - they are exclusive of each other. Look to your definitions TP, even your own prophet is on record stating that the Jesus of mormonism is DIFFERENT from the Jesus of Christianity.
Which is why I use the “orthodox Christian” label to show the difference.
And the use of orthodox is "having the right opinion", from orthos ("right", "true", "straight") + doxa ("opinion" or "praise", related to dokein, "to think"). Which means mormonism is not 'right'
The early church had the same problem with groups with heretical doctrines wanting to be called Christian and thinking theirs was the only true church. Today, we call them Gnostics and they were determined by the Councils not to be considered Christian.
The Gnostic heresies are precisely why the early creeds were developed and the canon solidified. They are both measuring sticks of orthodox (correct) doctrine versus heterodox doctrine.
And many who insist that you can be outside orthodox Christian doctrine and still be a ‘Christian’, forget that there is a term called “pseudo-Christian” which is what most people actually mean when they say Mormons are not Christian, that they are ‘pseudo-Christian’, simply based upon their heterodox doctrines and practices.