The Trinity and all of its supporting doctrines are all circular in reasoning

[360watt]

That's the best rebuttal you can come up with?

Definition of Son of Man​

1: a human being
2: often capitalized S : God's messiah destined to preside over the final judgment of humankind

Definition of SON OF MAN

a human being; God's messiah destined to preside over the final judgment of humankind… See the full definition

www.merriam-webster.com

Show us where the term "Son of Man" has any other meaning besides the fact it means human being. Do so by quoting scriptural context (surrounding words, verses, or chapters). And since that expression "Son of Man" appears 82 times in the New Testament, you need to show context for all 82 instances.

You've got your work cut out; haven't you?


Ready, set, go!

Son of Man is a reference to the redemptive purpose of Jesus, not that he is only a mortal man. Its showing Jesus humbling Himself to be the ultimate sacrificial Lamb.

 

[360watt]

From GotQuestions:

Son of Man is a title of deity. Ezekiel may have been a son of man, but Jesus is the Son of Man. As such, Jesus is the supreme example of all that God intended mankind to be, the embodiment of truth and grace (John 1:14). In Him “all the fullness of the Deity lives in bodily form” (Colossians 2:9). For this reason, the Son of Man was able to forgive sins (Matthew 9:6). The Son of Man is Lord of the Sabbath (Mark 2:28). The Son of Man came to save lives (Luke 9:56; 19:10), rise from the dead (Mark 9:9), and execute judgment (John 5:27). At His trial before the high priest, Jesus said, “I say to all of you: From now on you will see the Son of Man sitting at the right hand of the Mighty One and coming on the clouds of heaven” (Matthew 26:64). This statement immediately ended the trial, as the court accused the Lord of blasphemy and condemned Him to death (verses 65–66).

 

[360watt]

At no time did Jesus send holy spirit, so I don't know why you're even asking that question, as if to say Jesus did it. Below is what Jesus himself said.


“But the Helper, the Holy Spirit, whom the Father will send in My name, He will teach you all things and will bring to your remembrance all things that I have said to you.” (John 14:26 – Berean Literal Bible)

John 14 BLB

I will address your other two rhetorical questions in separate posts by using scripture.

John 15:26 kjv​

​

26 But when the Comforter is come, whom I will send unto you from the Father, even the Spirit of truth, which proceedeth from the Father, he shall testify of me:

KJV isn't the only translation that has this either. It is both the Father and Jesus sending the Holy Spirit.

Aside from this.. Jesus, in Matthew 18 says he will dwell 'in the midst' of a congregation.. a group sorting out disputes among each-other.

Jesus does this through the Holy Spirit. A mortal man can do that?

Jesus also saw Phillip under a tree when He was nowhere near Phillip. A mortal man can do that?

And to address the fact of Jesus doing things by the Father's authority. There were times when He was doing this by His own authority.. such as when He said what could be done on the Sabaath.. laying aside laws laid down by God in the OT.

Also there is the concept of agency in Judaism.. where the agent- ie. Jesus.. would be doing things on behalf of another ie the Father.. and the agent is seen as having the same standing as the originator of the message. They see the agent.. effectively as the originator.

This is why the Pharisees accused Him of blasphemy and sort to stone him.. because he was making Himself 'equal with God'