The chief priest is not asking Jesus for information about what the witnesses said. He is asking Jesus to prove what the witnesses said is wrong. AT: "What is your response to what the witnesses are testifying against you?"
This is an important title that describes the relationship between the Christ and God. (See: rc://en/ta/man/translate/guidelines-sonofgodprinciples)
Here "living" contrasts the God of Israel to all the false gods and idols that people worshiped. Only the God of Israel is alive and has power to act. See how you translated this in Matthew 16:16.
This is an idiom that Jesus uses to mean "yes" without being completely clear about what he means. AT: "You are saying it" or "You are admitting it" (See: rc://en/ta/man/translate/figs-idiom)
Here "you" is plural. Jesus is speaking to the high priest and to the other persons there. (See: rc://en/ta/man/translate/figs-you)
Possible meanings are 1) the phrase "from now on" is an idiom that means they will see the Son of Man in his power at some time in the future or 2) the phrase "from now on" means that from the time of Jesus' trial and onward, Jesus is showing himself to be the Messiah who is powerful and victorious.
Jesus is speaking about himself in third person. (See: rc://en/ta/man/translate/figs-123person)
Here "Power" refers to God. The "right hand of Power" is an idiom that means that Christ will rule as God, with God’s authority. AT: "I will sit in the position of God" (See: rc://en/ta/man/translate/figs-idiom)
"riding to earth on the clouds of heaven"