Here is an example of a
sprite in game that can be edited using the Over World Editor.
Those sprites can be edited using the Over World Editor. Such as the Hero sprite from Pokemon Emerald that I've given the link to.
You can change the sprite while it is walking, running, using a bike, when it is about to use the fly move etc.
Each Protagonist sprite contains a lot of frames as I've said, like walking, running etc.
Since it is a sprite editor, you can edit the color or the overall appearance of the said sprite.
It is a simple tool, it does not need a brief guide. It is only for editing sprites in-game.
Note:
NPCs, Gym Leader, Rivals, Champion can all be edited.
Another Note:
Most NPC use the same pallete, make sure to watch the video I've given out so you won't mess up the pallete.