I agree that he did seek out God. But then there's this...
The fool has said in his heart, “There is no God.” They are corrupt, they have committed abominable deeds; There is no one who does good. The LORD has looked down from heaven upon the sons of men To see if there are any who understand, Who seek after God. They have all turned aside, together they have become corrupt; There is no one who does good, not even one.[Psalm 14:1-3] Here we see that the fools, IOW the wicked, are not looking, seeking for God.
What then? Are we better than they? Not at all; for we have already charged that both Jews and Greeks are all under sin; as it is written, “THERE IS NONE RIGHTEOUS, NOT EVEN ONE; THERE IS NONE WHO UNDERSTANDS, THERE IS NONE WHO SEEKS FOR GOD; ALL HAVE TURNED ASIDE, TOGETHER THEY HAVE BECOME USELESS; THERE IS NONE WHO DOES GOOD, THERE IS NOT EVEN ONE.”[Romans 3:9-12]
So, the wicked do not seek God. Now you have presented unto yourself an conundrum. There are none who seek God, in proper context it means the wicked. Now, this demon possessed man that sought Jesus was as wicked as they come. Why did he seek Him?