I honestly have always seen Scarface as a spirit possessed doll even if Zatanna says other wise I've always suspected Scarface is a spirit that possesses a doll and uses it to influence people. I mean my main theory is that the spirit can come and go when it wants and Zatanna misread what she was sensing from the dummy. I think a good story arc would be for Deadman to show up help Batman with a random case then Scarface turns up and Deadman sees another spirit hiding nearby and it's revealed Scarface is a vengeful evil spirit of a gangster. I also like this idea as it adds to the ventriloquist especially if in life Scarface was a bully and in death he takes advantage of Arnold's own mental illness. I think that'd expanding on Scarface like that would be cool especially if he had history with Cyrus Gold aka Solomon Grundy.