Jacob observed for a little while, and when it became obvious that the Wisp of Virgo was not going to survive, he knew he had to intervene, not because he was afraid of the Grim Lich Pascal getting away with the Cosmic Vestige but because he didn't know if he would be able to earn the acknowledgment of Virgo after her Wisp's defeat.
Without hesitation, Jacob crouched low, his eyes locked on the Grim Lich Pascal, who stood in the midst of the battlefield, utterly engrossed in his assault against the Wisp of Virgo.
The Lich's bony fingers clutched his twisted, ebony staff, channeling dark energy to command his Dark Being Army. It was clear to Jacob that Pascal had no idea another person had entered the Tower. After all, how could he? The Legendary Master Key had granted Jacob entry, something Pascal would never have imagined possible.
With the Lich's attention fully occupied, this was the perfect opportunity.