On second thought, I've run into a new problem.
Now, I tried indexing the image over and over again using IrfanView, but each time I load the indexed image into unLZGBA, it tells me the image ISN'T INDEXED.
I don't get if...If I'm doing everything right to index the sprite, why is unLZGBA telling me this?
Edit:
I've figured out a lot more with what's going. Apparently, dragging my clean sprite over the indexed version to clean it up screws it and makes un-indexed somehow. I'm able to export the sprite ig I don't clean it up, but the sprite is all pixely, and the changes don't happen with the rom when I load it into VBA.
Also, if I do load the edited sprite into unLZGBA, export it and then switch to a different image and back to Oak...image is Oak again.
Edit 2:
Fixed the indexing problem and managed to successfully replace Oak's sprite...except, when I boot up the rom, he's still...Oak. Damn it. Even unLZGBA reverts after I exit or exit and return.