Dr. Strange vs Randall Flagg (Man in Black)

I have not seen this battle yet and after seeing dark tower I was wondering who would win in a battle of magic between the Randall Flagg (Man in Black) and Doctor Strange.

vs

Randall Flagg is a low mid-tier. Strange is herald tier.

Randall is powerful, but I don't think he is Strange level especially classic Strange level.

Isn't Randall considered a demon? or his powers are demonic? Thought that would give him a decent chance against Strange

Strange stomps. He operates on an entirely different level.

Demons are all over the place in tier.

Mid tier Vs herald tier. Sigh....