(JoJo's Bizarre Adventure) D4C's ability is to "allow neighboring worlds to exist simultaneously in the same location" but what exactly does that mean?

It depends on what type of third separates the three notes.for example: if you have two mayor thirds is an "aumented chord"if you have two minor thirds is an "diminued chord"if you have one mayor first and then one minor is a "mayor chord"and inverted is a "minor chord"