"Hollow Purple" (Kyoshiki Murasaki) represents the collision of "Cursed Technique Lapse: Blue" and "Cursed Technique Reversal: Red" to create an "imaginary mass".
If you need a "paper" for musical analysis or to play the piece yourself:
You can find the original version by Alisa Okehazama on YouTube .
For academic or fan research into the meaning behind the sound: