The anti-christ is supposed to be 30 years old when he begins his "ministry" performing false miracles. This is to mimic Yeshua who also started his ministry at 30 years old and ministered for 3-3.5 years.
This goes back to end time prophecy where the anti-christ is supposed to reign for 3.5 years. Everything Satan does is to mock, mimic, and deceive. He is supposed to trick people into believing he is the Messiah by copying the true God.