@5, like I said, I can't help you. You've left out a lot of information that prevents me from answering your questions, thereby asking generic questions that are nearly impossible to answer. If your editor is for an engine like UE4 or Godot, and you've acquired the source code, and are able to integrate hat editor into the rest of the Godot/UE4 editors without causing major issues with the codebase, then you can do that. If the editor is for Unity, then the answer is no, you can't. That's the simple answer. But considering how tyrannical Unity is, it wouldn't surprise me if there's a clause in the license agreement that says you can't do that. You could write an asset, but I really wouldn't if your the only one using it.
"On two occasions I have been asked [by members of Parliament!]: 'Pray, Mr. Babbage, if you put into the machine wrong figures, will the right answers come out ?' I am not able rightly to apprehend the kind of confusion of ideas that could provoke such a question." — Charles Babbage.