Sasuke Uchiha had spent ten days inside the deep green slug, undergoing fusion modification. Wu Yu and Tsunade had all but given up hope of success.
Those who truly succeeded at the fusion, like Karin, needed only a day or so. Someone like Wu Yu, who had lingered inside the slug for nearly a month, still could not be considered a success.
If Jade Rabbit had not been inside Wu Yu back then, producing a remarkable reaction with the slug's fusion "surgery" and, through a lucky coincidence, bringing about his half-sage body, Wu Yu would probably have failed the modification and forever remained hopeless at Sage Mode.
Yet now, a sudden change occurred in Sasuke Uchiha. Tsunade's Cursed Seal on his body seemed to be rejected by something. It activated on its own, spread across his entire body, and began fluctuating violently. The sleeping Sasuke Uchiha furrowed his brow and trembled all over, as though suffering unbearable pain—
Seeing this, Tsunade had intended to retrieve her cursed seal from Sasuke before its power went out of control, turned against him, and caused irreparable damage. But just then, the emerald-green, teardrop-shaped marks, already on the brink of collapse, began burning across his skin. As though undergoing a thorough tempering, they transformed in swaths into purple tomoe amid violent chakra fluctuations—
As the upheaval slowly subsided, the purple tomoe markings receded and gathered together, leaving three purple tomoe on the back of Sasuke Uchiha's neck. They resembled a purple version of Orochimaru's original Heaven Curse Mark, or the imprint of a purple Three-Tomoe Sharingan staring at Wu Yu and Tsunade.
Sasuke Uchiha's tightly furrowed brow slowly relaxed, and his body stopped trembling.
Tsunade and Wu Yu exchanged a look. Tsunade asked, "Katsuyu, what exactly happened?"
The deep green slug explained in her