C2307 Dark Abyss
If he used the Black Yellow Source Qi alone to set up a barrier, he wouldn't be able to stop the Ninth Underworld King even for a moment.
Therefore, Su Bai gave up on the Heavenly Secrets Compass and threw it away. With the support of the Heavenly Secrets Compass, he managed to stop the Ninth Underworld King for four breaths of time.
Although it was only four breaths of time