5E does not have much in the way of "at will" magic. An arcane trickster rogue has an upgraded version of the mage hand cantrip. That is the closest you get to at will telekinesis.


5E does not have exceptional races. So the shadow demon would need to use class levels to replace some lost features. I think a trickery cleric or an echo knight fighter are the closest matches for the shadow duplicate.


In summary, 5E will not recreate these characters very well. Your new characters at their height might feel like aspects of your old characters.