The lights in the Hokage's Office stayed on all night. Dust-covered files and the latest intelligence from the Anbu lay piled before Tsunade. Finding a suitable "Impure World Reincarnation vessel" was no easy task. It needed enough strength to house Tobirama's soul, and its abilities in life had to be useful for gathering intelligence. She also had to consider how controllable it would be and what chain reactions it might trigger. More importantly, Orochimaru's trail was like a venomous snake hidden in the fog. Even Konoha's intelligence network struggled to pinpoint his main base.
Just as Tsunade was at her wits' end, an old report from the southern border concerning "unusual activity in the Ancient Kingdom of Roran's dragon vein" happened to arrive among the intelligence reports. It mentioned that the dragon vein contained enormous energy suspected to be connected to space-time. The report itself had received little attention, but a flash of insight struck Tsunade!
The dragon vein... space-time energy... Orochimaru has always had an extraordinary interest in forbidden powers like these!
After defecting, Orochimaru had made Rōran's dragon vein, with its vast space-time energy, one of his research priorities. He sought to understand and control that power, not merely for immortality or strength, but to test his theories, and perhaps... to trade for or investigate "knowledge" from other times and spaces.
A bold conjecture surfaced in her mind. She immediately ordered all records concerning the Ancient Kingdom of Roran, the dragon vein, and abnormal energy fluctuations in the surrounding region over recent years to be gathered for cross-analysis.
After several days of investigation, the Anbu finally identified a secluded valley near the Rōran ruins, on the border between the Land of Wind and the Land of Rivers. Analysis of residual energy and scattered eyewitness reports suggested that Orochimaru