I am so sorry for holding this up for so long, especially after I pestered you guys so much. I've posted now. 

[hider=To clarify]
Chara can be seen by both Frisk and Flowey, Gaster, and Sans whenever he uses his magic eye. To anyone else, they can only see Chara when Chara wants to be seen.

Gaster can be seen by anybody at all times, he’s just not noticed very easily. He usually has to point himself out, except to Sans, Papyrus, Frisk, or Flowey. 
Why not Chara? Because Chara [color=fff79a][i]A)[/i][/color] doesn’t care, and [color=fff79a][i]B)[/i][/color] does not yet see Gaster as a threat.

I am only puppeting Papyrus for now.[/hider]