How do I merge multiple objects so I can sculpt it? As the title implies, how do I do this? Is there maybe an add-on to make it easier? I did ctrl-J to join all the bodies together, but they really weren't connected as one.
Search in the add-ons window "bool tool".
Select the two mesh that your want to join.
Go to the object menu in the view-port,bool tool operation, and select "union".
And wuala! you have a unified object.


You can do this without the add-on using only modifiers but its a little bit wonky 
Hope it helps!