I searched to see if this topic had been posted and didn't see anything in relation to it except for the Reality Shift in the Sorcery world.  I have had no trouble with Reality Shifts until now.  In The World that Never Was, if I DO manage to do it correctly, I have no idea how.  I feel like a dummy, guys.  In which direction am I meant to be moving the stylus?  In the same direction as the white chains/pods, or what?  I've tried everything and most of the time, it doesn't work.  I imagine Sora is a little tired of getting hit by buildings at this point. 

 

Thank you all in advance for any advice you can give me!  I'm sorry if anyone's asked about this particular Reality Shift before and I missed it! 

you want to slash the little grey parts of the chains in as few hits as possible

From the Kh wiki:

 

Nightmare's End and Mirage Split are Reality Shifts for The World That Never Was. Once the Reality Shift is started, several cycling chains appear on the touch screen. The player must use the stylus to cut through each chain's weak link with three cuts or less. Once Nightmare's End of Mirage Split are activated, Sora and Riku will swing the summoned Keyblade to cut apart obstacles or inflict damage to any nearby enemies.

Nightmare's End is also used by Sora to cleave the white-striped skyscrapers that block his path and fall from the sky, as well as to destroy the skyscrapers that Xemnas throws while also stunning him.

The point of TWTNW reality shifts is to cut through all links in three times or less (one time is recommended). You have to study the pattern and determine which way you move the stylus to go through all links at once. Note: the patterns always change.