## he who confuses you will bear his own judgment, whoever he is ##
"I do not know who is confusing you, but God will punish that person"
## confuses you ##
"causes you to be uncertain about what is truth" (see UDB) or "stirs up trouble among you"
## will bear his own judgment ##
"will be punished by God"
## whoever he is ##
This can mean 1) Paul does not know the names of the people who are telling the Galatians that they need to obey the Law of Moses or 2) Paul does not want the Galatians to care about whether those who "confuse" them are rich or poor or great or small or religious or not religious.