Relm sprite editor?

http://www.simulationnation.com/zeemis/f...09#pid2709

It is the one that is titled FF3usSpriteEditor.

As for your Dawn of Souls sprite, unless you mean it as a sprite you made to be used in Final Fantasy VI there is nothing that this sprite editor can do for you.
This sprite editor is for Final Fantasy VI (III) exclusively. If you want to touch up a sprite for another game my suggestion is to look for a sprite editing program for that game (if one even exists) and if not, simply used Graphics Gale to do it. However I'm none too sure how to replace the sprite unless you use Cd Mage to extract the files and then import then new file.