Since pockets of Oblivion are illusions and "your mind is trying to make sense of it", wouldn't it be fitting to add FX to the area, alike to Dragon Age's Fade?
The Realms of Oblivion aren't illusions, they're most certainly real. The only "illusion" is that mortals see them as spherical bodies. Each plane is an infinite mass of infinite size, but due to a visual phenomena caused by mortal mental stress, the mortal eye registers them as bubbles within a space.