Is God singular or plural Person?
Isaiah 43:10-11 KJV
Ye are my witnesses, saith the Lord , and my servant whom I have chosen: that ye may know and believe me, and understand that I am he: before me there was no God formed, neither shall there be after me. I, even I, am the Lord ; and beside me there is no saviour.
obviously God is singular Person.

What will the True Christ do?
Psalm 89:26-27 God said,
He shall cry unto me, Thou art my father, my God, and the rock of my salvation. Also I will make him my firstborn, higher than the kings of the earth.

What will the Antichrist do?
Daniel 7:25 KJV
And he shall speak great words against the most High.
2 Thessalonians 2:4 KJV
Who opposeth and exalteth himself above all that is called God, or that is worshipped; so that he as God sitteth in the temple of God, shewing himself that he is God.
Revelation 13:6 KJV
And he opened his mouth in blasphemy against God.

In 4th AD Roman Bishops accepted another Christ (false)
"Roman & Saxon Jesus" = God.
Is Blasphemy against the God of Isreal.