1. I would recommend doing this on a save file where you are pretty far in the game, as I have tested this and it didn't work on a new game.
2. This may take multiple tries to work, so don't give up!
3. I did this in version 1.88. Later versions seem to have fixed this bug, so you'll have to downgrade your game through the betas menu if you want to use this method.

To do this you need:

• to have not fought lillith's second phase
  
• yellow magic
  
• rescued ribbon's friends

Once you have these, now you can move on to the next step!

start the flying section, and make sure that, near the end, you switch to yellow magic. After you defeat the last fairy, you need to get into the middle and hold down the magic button. when the text box pops up continue holding the magic button and press start, then press and hold the magic button then when the next text box pops up you can let go of your controller (or keyboard) and the beam should stay there, which means you did it right! now you just wait and your combo should keep going up. getting the achievement might take a while though.

If anyone could test ths out a bit more than i did, so that other people know when this works, that would be great! and thanks for reading my guide! I really hope it helped! If you have any feedback I would like to hear it!