This man will be revealed by God when he who is now preventing him from being revealed will have been removed by God.

2 Thessalonians 2:6-8

6 You also know that there is something (OR, someone) that is preventing this man from being revealed {from revealing himself}. This man is being ◄held back/restrained► now for him to be revealed {that he reveal himself} at the time that God has planned [MTY]. 7 Although Satan is already secretly causing people to reject God’s laws, ◄the one/God► who is preventing this man from revealing himself now will continue to prevent him from doing that until he/God removes him. 8 It is then that God will allow this man, who rejects God’s laws completely, to be revealed {to reveal himself}. Then the Lord Jesus will destroy him, by simply commanding it [MTY]. Jesus, by his own glorious arrival, will cause him to become completely powerless.