"God himself shall come down among the children of men, and shall redeem his people. And because he dwelleth in flesh he shall be called the Son of God" ... "being the Father and the Son — The Father, because he was conceived by the power of God; and the Son, because of the flesh; thus becoming the Father and Son — And they are one God "- Mosiah 15:1-4

“Teach them that redemption cometh through Christ the Lord, who is the very Eternal Father. Amen." - Mosiah 16:15

“Now Zeezrom saith again unto him: Is the Son of God the very Eternal Father? And Amulek said unto him: Yea, he is the very Eternal Father of heaven and of earth, and all things which in them are; he is the beginning and the end, the first and the last; and he shall come into the world to redeem his people; and he shall take upon him the transgressions of those who believe on his name; and these are they that have eternal life, and salvation cometh unto none else.” - Alma 11:38-40

"Behold, I am he who was prepared from the foundation of the world to redeem my people. Behold I am Jesus Christ. I am the Father and the Son. " - Ether 3:14

I agree they are polytheists and modalists at the same time by their language. They are even Trinitarian in the Book of Mormon. Satan is the author of confusion. Mormons are insane when they say Jesus is "the Father, because he was conceived by the power of God." A person who is conceived is NOT the father but son so their explanation makes no sense. When they say Jesus is the "eternal father" they are borrowing from Is. 9.6 the son as head, founder, ruler, chief, term of respect or honor, originator....they take that and misapply it to the Father in the NT. Obviously this is not the sense used for the Father in the NT because Jesus prays to the Father, not to Himself. Jesus is not the Father. Modalism and Polytheism are false. Mormons are going to Hell.