The Sleeper is probably the most viable character for making a show.
Everyone else is either too high in melodrama or too deep in depravity or just too expensive in FX. America does not want to see a fat telekinetic in a dramatically sympathetic lead role, nor do they want an effeminate alien lothario as a lead.
Basically take the base personality they gave Constantine then make him a methamphetamine addict. Make him a part time detective for hire/fixer and a thief. Then build the WC universe around him.
